diff --git a/app.py b/app.py
index 1a28c9a..c6bf00c 100644
--- a/app.py
+++ b/app.py
@@ -21,12 +21,13 @@ from handlers.api import (
 BASE_DIR = os.path.dirname(os.path.abspath(__file__))
 
 
-def make_app(session_factory=None):
+def make_app(session_factory=None, debug=False):
     """Create and configure the Tornado application.
 
     Args:
         session_factory: SQLAlchemy session factory. If None, API
             endpoints that require a database will not work.
+        debug: Enable debug mode (auto-reload, stack traces).
 
     Returns:
         A configured ``tornado.web.Application`` instance.
@@ -45,18 +46,19 @@ def make_app(session_factory=None):
         template_path=os.path.join(BASE_DIR, "templates"),
         static_path=os.path.join(BASE_DIR, "static"),
         session_factory=session_factory,
-        debug=True,
+        debug=debug,
     )
 
 
 @click.command()
 @click.option("--port", default=8888, type=int, help="Port to listen on.")
-def main(port):
+@click.option("--debug", is_flag=True, help="Enable debug mode.")
+def main(port, debug):
     """Start the web server."""
     engine = get_engine()
     init_db(engine)
     session_factory = get_session_factory(engine)
-    app = make_app(session_factory=session_factory)
+    app = make_app(session_factory=session_factory, debug=debug)
     app.listen(port)
     print(f"Server started at http://localhost:{port}")
     tornado.ioloop.IOLoop.current().start()
diff --git a/handlers/api.py b/handlers/api.py
index 528a6bc..dd0dcf2 100644
--- a/handlers/api.py
+++ b/handlers/api.py
@@ -1,6 +1,8 @@
 """REST API handlers for game operations."""
 
+import collections
 import json
+import time
 from datetime import datetime, timezone
 
 import tornado.web
@@ -9,6 +11,27 @@ from game.factory import BoardFactory, DIRECTIONS
 from models.category import Category
 from models.game import Game, Word
 
+# Per-IP rate limit: tracks {ip: deque of timestamps}
+_rate_buckets = collections.defaultdict(collections.deque)
+
+# Limits: (max_requests, window_seconds)
+RATE_LIMITS = {
+    "default": (60, 60),
+    "new_game": (10, 60),
+}
+
+
+def _check_rate(ip, bucket="default"):
+    max_requests, window = RATE_LIMITS[bucket]
+    now = time.monotonic()
+    timestamps = _rate_buckets[f"{bucket}:{ip}"]
+    while timestamps and timestamps[0] <= now - window:
+        timestamps.popleft()
+    if len(timestamps) >= max_requests:
+        return False
+    timestamps.append(now)
+    return True
+
 
 class BaseAPIHandler(tornado.web.RequestHandler):
     """Base handler for JSON API endpoints."""
@@ -20,6 +43,14 @@ class BaseAPIHandler(tornado.web.RequestHandler):
         Session = self.application.settings["session_factory"]
         return Session()
 
+    def check_rate_limit(self, bucket="default"):
+        """Return True if request is allowed, else write 429 and return False."""
+        if not _check_rate(self.request.remote_ip, bucket):
+            self.set_status(429)
+            self.write(json.dumps({"error": "Too many requests"}))
+            return False
+        return True
+
     def write_error(self, status_code, **kwargs):
         self.write(json.dumps({"error": self._reason}))
 
@@ -32,6 +63,9 @@ class CategoriesHandler(BaseAPIHandler):
         try:
             categories = session.query(Category).all()
             self.write(json.dumps([{"id": c.id, "name": c.name} for c in categories]))
+        except Exception:
+            session.rollback()
+            raise
         finally:
             session.close()
 
@@ -39,28 +73,72 @@ class CategoriesHandler(BaseAPIHandler):
 class NewGameHandler(BaseAPIHandler):
     """``POST /api/game/new`` -- create a new game.
 
-    Expects JSON body with ``category_id`` and optional ``board_size`` (8-20).
+    Expects JSON body with ``category_id`` and optional ``board_size`` (8-20)
+    and ``word_count`` (3-30).
     """
 
     def post(self):
+        if not self.check_rate_limit("new_game"):
+            return
         session = self.get_session()
         try:
-            data = json.loads(self.request.body)
+            try:
+                data = json.loads(self.request.body)
+            except (json.JSONDecodeError, TypeError):
+                self.set_status(400)
+                self.write(json.dumps({"error": "Invalid JSON"}))
+                return
+
+            if "category_id" not in data:
+                self.set_status(400)
+                self.write(json.dumps({"error": "category_id is required"}))
+                return
+
             category_id = data["category_id"]
-            board_size = data.get("board_size", 10)
+
+            try:
+                board_size = int(data.get("board_size", 10))
+            except (TypeError, ValueError):
+                self.set_status(400)
+                self.write(json.dumps({"error": "board_size must be a number"}))
+                return
             board_size = max(8, min(20, board_size))
 
+            try:
+                word_count = int(data.get("word_count", 8))
+            except (TypeError, ValueError):
+                self.set_status(400)
+                self.write(json.dumps({"error": "word_count must be a number"}))
+                return
+            word_count = max(3, min(30, word_count))
+
+            category = session.query(Category).filter_by(id=category_id).first()
+            if not category:
+                self.set_status(404)
+                self.write(json.dumps({"error": "Category not found"}))
+                return
+
             factory = BoardFactory(session)
             game, words = factory.create(
                 category_id=category_id,
                 board_size=board_size,
+                word_count=word_count,
             )
+
+            if not words:
+                self.set_status(500)
+                self.write(json.dumps({"error": "Failed to generate board with words"}))
+                return
+
             session.add(game)
             for w in words:
                 session.add(w)
             session.commit()
 
             self.write(json.dumps(self._game_to_dict(game)))
+        except Exception:
+            session.rollback()
+            raise
         finally:
             session.close()
 
@@ -108,6 +186,9 @@ class GameStateHandler(BaseAPIHandler):
                     }
                 )
             )
+        except Exception:
+            session.rollback()
+            raise
         finally:
             session.close()
 
@@ -120,6 +201,8 @@ class GuessHandler(BaseAPIHandler):
     """
 
     def post(self, game_id):
+        if not self.check_rate_limit():
+            return
         session = self.get_session()
         try:
             game = session.query(Game).filter_by(id=game_id).first()
@@ -128,7 +211,12 @@ class GuessHandler(BaseAPIHandler):
                 self.write(json.dumps({"error": "Game not found"}))
                 return
 
-            data = json.loads(self.request.body)
+            try:
+                data = json.loads(self.request.body)
+            except (json.JSONDecodeError, TypeError):
+                self.set_status(400)
+                self.write(json.dumps({"error": "Invalid JSON"}))
+                return
 
             if "word" in data:
                 result = self._handle_text_guess(session, game, data["word"])
@@ -140,10 +228,15 @@ class GuessHandler(BaseAPIHandler):
                 return
 
             self.write(json.dumps(result))
+        except Exception:
+            session.rollback()
+            raise
         finally:
             session.close()
 
     def _handle_text_guess(self, session, game, guess_text):
+        if not isinstance(guess_text, str):
+            return self._miss_response(game, session)
         guess_text = guess_text.upper().strip()
         word = (
             session.query(Word)
@@ -159,7 +252,7 @@ class GuessHandler(BaseAPIHandler):
         grid = game.grid
         try:
             letters = "".join(grid[c["row"]][c["col"]] for c in cells)
-        except (IndexError, KeyError):
+        except (IndexError, KeyError, TypeError):
             return self._miss_response(game, session)
 
         word = (
diff --git a/seed.py b/seed.py
index 96d85c1..67b161c 100644
--- a/seed.py
+++ b/seed.py
@@ -23,6 +23,21 @@ SEED_DATA = {
         "CRANE",
         "MOOSE",
         "RAVEN",
+        "JAGUAR",
+        "PARROT",
+        "TURTLE",
+        "SALMON",
+        "FERRET",
+        "COYOTE",
+        "OSPREY",
+        "LIZARD",
+        "BADGER",
+        "PELICAN",
+        "MONKEY",
+        "RABBIT",
+        "IGUANA",
+        "CONDOR",
+        "JACKAL",
     ],
     "colors": [
         "CRIMSON",
@@ -45,6 +60,21 @@ SEED_DATA = {
         "JADE",
         "CYAN",
         "MAUVE",
+        "COBALT",
+        "COPPER",
+        "EBONY",
+        "PEACH",
+        "CREAM",
+        "LEMON",
+        "ORCHID",
+        "SALMON",
+        "SIENNA",
+        "KHAKI",
+        "LILAC",
+        "PEARL",
+        "CHARCOAL",
+        "MAGENTA",
+        "EMERALD",
     ],
     "food": [
         "PIZZA",
@@ -67,6 +97,129 @@ SEED_DATA = {
         "CURRY",
         "BAGEL",
         "FUDGE",
+        "SHRIMP",
+        "CHEESE",
+        "BUTTER",
+        "CHERRY",
+        "PEPPER",
+        "GINGER",
+        "PRETZEL",
+        "BRISKET",
+        "NOODLE",
+        "OYSTER",
+        "TURNIP",
+        "RADISH",
+        "CELERY",
+        "COOKIE",
+        "BISQUE",
+    ],
+    "sports": [
+        "SOCCER",
+        "TENNIS",
+        "BOXING",
+        "RUGBY",
+        "GOLF",
+        "DIVING",
+        "ROWING",
+        "HOCKEY",
+        "FENCING",
+        "ARCHER",
+        "SPRINT",
+        "DISCUS",
+        "SQUASH",
+        "KARATE",
+        "JUDO",
+        "RELAY",
+        "SLALOM",
+        "CRAWL",
+        "VAULT",
+        "SERVE",
+        "VOLLEY",
+        "TACKLE",
+        "PADDLE",
+        "JAVELIN",
+        "HURDLE",
+    ],
+    "space": [
+        "PLANET",
+        "GALAXY",
+        "NEBULA",
+        "COMET",
+        "ORBIT",
+        "QUASAR",
+        "PULSAR",
+        "LUNAR",
+        "SOLAR",
+        "METEOR",
+        "AURORA",
+        "ECLIPSE",
+        "ZENITH",
+        "CRATER",
+        "COSMOS",
+        "PHOTON",
+        "PLASMA",
+        "ROCKET",
+        "SATURN",
+        "VENUS",
+        "MARS",
+        "PLUTO",
+        "TITAN",
+        "VORTEX",
+        "FLARE",
+    ],
+    "nature": [
+        "RIVER",
+        "OCEAN",
+        "CANYON",
+        "FOREST",
+        "DESERT",
+        "ISLAND",
+        "GLACIER",
+        "MEADOW",
+        "VALLEY",
+        "SUMMIT",
+        "LAGOON",
+        "TUNDRA",
+        "MARSH",
+        "CLIFF",
+        "DELTA",
+        "FJORD",
+        "GROVE",
+        "RIDGE",
+        "CORAL",
+        "BROOK",
+        "DUNE",
+        "GEYSER",
+        "CAVERN",
+        "RAPIDS",
+        "SAVANNA",
+    ],
+    "music": [
+        "GUITAR",
+        "PIANO",
+        "DRUMS",
+        "VIOLIN",
+        "FLUTE",
+        "CELLO",
+        "BANJO",
+        "ORGAN",
+        "HARP",
+        "TRUMPET",
+        "RHYTHM",
+        "MELODY",
+        "CHORD",
+        "TEMPO",
+        "FORTE",
+        "TREBLE",
+        "OCTAVE",
+        "SONATA",
+        "BALLAD",
+        "OPERA",
+        "HYMN",
+        "LYRIC",
+        "CHORUS",
+        "BRIDGE",
+        "DUET",
     ],
 }
 
@@ -80,14 +233,23 @@ def seed():
     for cat_name, words in SEED_DATA.items():
         existing = session.query(Category).filter_by(name=cat_name).first()
         if existing:
-            print(f"Category '{cat_name}' already exists, skipping.")
-            continue
-        cat = Category(name=cat_name)
-        session.add(cat)
-        session.flush()
+            cat = existing
+        else:
+            cat = Category(name=cat_name)
+            session.add(cat)
+            session.flush()
+
+        added = 0
         for w in words:
-            session.add(CategoryWord(category_id=cat.id, word=w))
-        print(f"Seeded category '{cat_name}' with {len(words)} words.")
+            exists = (
+                session.query(CategoryWord)
+                .filter_by(category_id=cat.id, word=w)
+                .first()
+            )
+            if not exists:
+                session.add(CategoryWord(category_id=cat.id, word=w))
+                added += 1
+        print(f"Category '{cat_name}': added {added} new words.")
 
     session.commit()
     session.close()
diff --git a/static/js/game.js b/static/js/game.js
index 799a90a..d9c84db 100644
--- a/static/js/game.js
+++ b/static/js/game.js
@@ -4,6 +4,7 @@
     let gameState = null;
     let timerInterval = null;
     let selectedCells = [];
+    let feedbackTimeout = null;
 
     // DOM refs
     const setupDiv = document.getElementById("game-setup");
@@ -11,12 +12,13 @@
     const categorySelect = document.getElementById("category-select");
     const boardSizeInput = document.getElementById("board-size");
     const sizeDisplay = document.getElementById("size-display");
+    const wordCountInput = document.getElementById("word-count");
+    const wordCountDisplay = document.getElementById("word-count-display");
     const newGameBtn = document.getElementById("new-game-btn");
     const gridTable = document.getElementById("grid-table");
     const wordList = document.getElementById("word-list");
     const wordInput = document.getElementById("word-input");
     const guessBtn = document.getElementById("guess-btn");
-    const submitSelectionBtn = document.getElementById("submit-selection-btn");
     const clearSelectionBtn = document.getElementById("clear-selection-btn");
     const guessFeedback = document.getElementById("guess-feedback");
     const timerEl = document.getElementById("timer");
@@ -27,32 +29,50 @@
 
     // Load categories
     async function loadCategories() {
-        const resp = await fetch("/api/categories");
-        const categories = await resp.json();
-        categorySelect.innerHTML = "";
-        categories.forEach(function (cat) {
-            const opt = document.createElement("option");
-            opt.value = cat.id;
-            opt.textContent = cat.name.charAt(0).toUpperCase() + cat.name.slice(1);
-            categorySelect.appendChild(opt);
-        });
+        try {
+            const resp = await fetch("/api/categories");
+            if (!resp.ok) throw new Error("Server error");
+            const categories = await resp.json();
+            categorySelect.innerHTML = "";
+            categories.forEach(function (cat) {
+                const opt = document.createElement("option");
+                opt.value = cat.id;
+                opt.textContent = cat.name.charAt(0).toUpperCase() + cat.name.slice(1);
+                categorySelect.appendChild(opt);
+            });
+        } catch (err) {
+            showFeedback("Failed to load categories.", "text-danger");
+        }
     }
 
     boardSizeInput.addEventListener("input", function () {
         sizeDisplay.textContent = this.value;
     });
 
+    wordCountInput.addEventListener("input", function () {
+        wordCountDisplay.textContent = this.value;
+    });
+
     // New game
     newGameBtn.addEventListener("click", async function () {
-        const categoryId = parseInt(categorySelect.value);
-        const boardSize = parseInt(boardSizeInput.value);
-        const resp = await fetch("/api/game/new", {
-            method: "POST",
-            headers: { "Content-Type": "application/json" },
-            body: JSON.stringify({ category_id: categoryId, board_size: boardSize }),
-        });
-        gameState = await resp.json();
-        showBoard();
+        try {
+            const categoryId = parseInt(categorySelect.value);
+            const boardSize = parseInt(boardSizeInput.value);
+            const wordCount = parseInt(wordCountInput.value);
+            const resp = await fetch("/api/game/new", {
+                method: "POST",
+                headers: { "Content-Type": "application/json" },
+                body: JSON.stringify({ category_id: categoryId, board_size: boardSize, word_count: wordCount }),
+            });
+            if (!resp.ok) {
+                const errData = await resp.json().catch(function () { return {}; });
+                throw new Error(errData.error || "Failed to create game");
+            }
+            gameState = await resp.json();
+            showBoard();
+        } catch (err) {
+            showFeedback(err.message || "Failed to create game.", "text-danger");
+        }
     });
 
     function showBoard() {
@@ -130,63 +150,85 @@
         const word = wordInput.value.trim();
         if (!word) return;
         wordInput.value = "";
-        await sendGuess({ word: word });
+        guessBtn.disabled = true;
+        try {
+            await sendGuess({ word: word });
+        } finally {
+            guessBtn.disabled = false;
+        }
     }
 
-    // Click selection
+    // Click selection — two-click: first letter, then last letter
     function onCellClick(row, col, td) {
         if (gameState.status === "completed") return;
 
-        // Check if already selected — deselect
-        const idx = selectedCells.findIndex(
-            function (c) { return c.row === row && c.col === col; }
-        );
-        if (idx !== -1) {
-            selectedCells.splice(idx, 1);
-            td.classList.remove("cell-selected");
+        // No start cell yet — this is the first click
+        if (selectedCells.length === 0) {
+            selectedCells.push({ row: row, col: col });
+            td.classList.add("cell-selected");
             updateSelectionButtons();
             return;
         }
 
-        // Validate straight line
-        if (selectedCells.length >= 2) {
-            if (!isValidExtension(row, col)) {
-                showFeedback("Selection must form a straight line.", "text-warning");
-                return;
-            }
+        // Clicking the same cell — deselect
+        if (selectedCells[0].row === row && selectedCells[0].col === col) {
+            clearSelection();
+            return;
         }
 
-        selectedCells.push({ row: row, col: col });
-        td.classList.add("cell-selected");
-        updateSelectionButtons();
-    }
+        // Second click — compute line from start to end
+        var startR = selectedCells[0].row;
+        var startC = selectedCells[0].col;
+        var dr = row - startR;
+        var dc = col - startC;
 
-    function isValidExtension(row, col) {
-        if (selectedCells.length < 2) return true;
-        const dr = selectedCells[1].row - selectedCells[0].row;
-        const dc = selectedCells[1].col - selectedCells[0].col;
-        const len = selectedCells.length;
-        const expectedRow = selectedCells[0].row + dr * len;
-        const expectedCol = selectedCells[0].col + dc * len;
-        return row === expectedRow && col === expectedCol;
+        // Validate straight line
+        var absDr = Math.abs(dr);
+        var absDc = Math.abs(dc);
+        if (absDr !== absDc && absDr !== 0 && absDc !== 0) {
+            showFeedback("Selection must form a straight line.", "text-warning");
+            clearSelection();
+            return;
+        }
+
+        var steps = Math.max(absDr, absDc);
+        if (steps === 0) return;
+
+        // Unit direction
+        var stepR = dr === 0 ? 0 : dr / absDr;
+        var stepC = dc === 0 ? 0 : dc / absDc;
+
+        // Build full cell list from start to end
+        var cells = [];
+        for (var i = 0; i <= steps; i++) {
+            cells.push({ row: startR + stepR * i, col: startC + stepC * i });
+        }
+
+        // Highlight all cells
+        cells.forEach(function (c) {
+            var cell = gridTable.querySelector(
+                'td[data-row="' + c.row + '"][data-col="' + c.col + '"]'
+            );
+            if (cell) cell.classList.add("cell-selected");
+        });
+
+        // Auto-submit
+        selectedCells = cells;
+        guessBtn.disabled = true;
+        sendGuess({ cells: cells }).then(function () {
+            guessBtn.disabled = false;
+            clearSelection();
+        });
     }
 
     function updateSelectionButtons() {
         if (selectedCells.length > 0) {
-            submitSelectionBtn.classList.remove("d-none");
             clearSelectionBtn.classList.remove("d-none");
         } else {
-            submitSelectionBtn.classList.add("d-none");
             clearSelectionBtn.classList.add("d-none");
         }
     }
 
-    submitSelectionBtn.addEventListener("click", async function () {
-        if (selectedCells.length === 0) return;
-        await sendGuess({ cells: selectedCells });
-        clearSelection();
-    });
-
     clearSelectionBtn.addEventListener("click", clearSelection);
 
     function clearSelection() {
@@ -199,25 +241,30 @@
 
     // Send guess to server
     async function sendGuess(payload) {
-        const resp = await fetch("/api/game/" + gameState.id + "/guess", {
-            method: "POST",
-            headers: { "Content-Type": "application/json" },
-            body: JSON.stringify(payload),
-        });
-        const result = await resp.json();
-        gameState.words = result.words;
-        gameState.status = result.status;
+        try {
+            const resp = await fetch("/api/game/" + gameState.id + "/guess", {
+                method: "POST",
+                headers: { "Content-Type": "application/json" },
+                body: JSON.stringify(payload),
+            });
+            if (!resp.ok) throw new Error("Server error");
+            const result = await resp.json();
+            gameState.words = result.words;
+            gameState.status = result.status;
 
-        if (result.correct) {
-            highlightFoundCells(result.cells);
-            renderWordList();
-            showFeedback("Found: " + result.word + "!", "text-success");
-        } else {
-            showFeedback("Not a match.", "text-danger");
-        }
+            if (result.correct) {
+                highlightFoundCells(result.cells);
+                renderWordList();
+                showFeedback("Found: " + result.word + "!", "text-success");
+            } else {
+                showFeedback("Not a match.", "text-danger");
+            }
 
-        if (result.status === "completed") {
-            onGameComplete(result.completed_at);
+            if (result.status === "completed") {
+                onGameComplete(result.completed_at);
+            }
+        } catch (err) {
+            showFeedback("Request failed. Try again.", "text-danger");
         }
     }
 
@@ -231,11 +278,13 @@
     }
 
     function showFeedback(msg, cls) {
+        if (feedbackTimeout) clearTimeout(feedbackTimeout);
         guessFeedback.textContent = msg;
         guessFeedback.className = "mt-2 " + cls;
-        setTimeout(function () {
+        feedbackTimeout = setTimeout(function () {
             guessFeedback.textContent = "";
             guessFeedback.className = "mt-2";
+            feedbackTimeout = null;
         }, 2000);
     }
 
diff --git a/templates/about.html b/templates/about.html
index 356a7bf..0449d95 100644
--- a/templates/about.html
+++ b/templates/about.html
@@ -1,8 +1,45 @@
 {% extends "base.html" %}
 
+{% block active_page %}{% set active_page = "about" %}{% end %}
+
 {% block title %}Word Search — About{% end %}
 
 {% block content %}
-<h2>About</h2>
-<p>About page coming soon.</p>
+<h2 class="mb-4">ℹ️ About</h2>
+
+<div class="content-section">
+    <h3>🧩 What is Word Search?</h3>
+    <p>
+        Word Search is a browser-based puzzle game where you find hidden words in a
+        grid of letters. Words can be placed horizontally, vertically, or
+        diagonally — forwards or backwards. The backend generates puzzles,
+        validates your selections, and tracks your progress in real time.
+    </p>
+</div>
+
+<div class="content-section">
+    <h3>🛠️ Built With</h3>
+    <ul>
+        <li><strong>Python</strong> — core language</li>
+        <li><strong>Tornado</strong> — async web framework</li>
+        <li><strong>Bootstrap 5</strong> — responsive UI</li>
+        <li><strong>Bootstrap Icons</strong> — interface icons</li>
+    </ul>
+</div>
+
+<div class="content-section">
+    <h3>✍️ Authors</h3>
+    <ul>
+        <li><strong>Mathew Guest</strong> — creator and developer</li>
+        <li><strong>🤖 Claude</strong> (Anthropic) — AI co-author</li>
+    </ul>
+</div>
+
+<div class="content-section">
+    <h3>📂 Source Code</h3>
+    <p>
+        The source code for this project will be available on GitHub.
+        <em>Link coming soon.</em>
+    </p>
+</div>
 {% end %}
diff --git a/templates/base.html b/templates/base.html
index 91e23b7..ad3a0d6 100644
--- a/templates/base.html
+++ b/templates/base.html
@@ -6,14 +6,20 @@
     <title>{% block title %}Word Search{% end %}</title>
     <link href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.3/dist/css/bootstrap.min.css"
           rel="stylesheet"
-          integrity="sha384-QWTKZyjpPEjISv5WaRU9OFeRpok6YcnS/1WR6zNiELmFp5mGg7gCjSP54e0TpoS"
+          integrity="sha384-QWTKZyjpPEjISv5WaRU9OFeRpok6YctnYmDr5pNlyT2bRjXh0JMhjY6hW+ALEwIH"
           crossorigin="anonymous">
+    <link href="https://cdn.jsdelivr.net/npm/bootstrap-icons@1.11.3/font/bootstrap-icons.min.css"
+          rel="stylesheet">
     <link rel="stylesheet" href="{{ static_url('css/theme.css') }}">
 </head>
 <body>
+    {% block active_page %}{% end %}
+
     <nav class="navbar navbar-expand-lg">
         <div class="container">
-            <a class="navbar-brand" href="/">Word Search</a>
+            <a class="navbar-brand" href="/">
+                <i class="bi bi-search"></i> Word Search
+            </a>
             <button class="navbar-toggler" type="button"
                     data-bs-toggle="collapse" data-bs-target="#navbarNav">
                 <span class="navbar-toggler-icon"></span>
@@ -21,16 +27,28 @@
             <div class="collapse navbar-collapse" id="navbarNav">
                 <ul class="navbar-nav ms-auto">
                     <li class="nav-item">
-                        <a class="nav-link" href="/">Home</a>
+                        <a class="nav-link {% if active_page == 'home' %}active{% end %}"
+                           href="/">
+                            <i class="bi bi-house-door"></i> Home
+                        </a>
                     </li>
                     <li class="nav-item">
-                        <a class="nav-link" href="/game">Play</a>
+                        <a class="nav-link {% if active_page == 'play' %}active{% end %}"
+                           href="/game">
+                            <i class="bi bi-controller"></i> Play
+                        </a>
                     </li>
                     <li class="nav-item">
-                        <a class="nav-link" href="/howtoplay">How to Play</a>
+                        <a class="nav-link {% if active_page == 'howtoplay' %}active{% end %}"
+                           href="/howtoplay">
+                            <i class="bi bi-question-circle"></i> How to Play
+                        </a>
                     </li>
                     <li class="nav-item">
-                        <a class="nav-link" href="/about">About</a>
+                        <a class="nav-link {% if active_page == 'about' %}active{% end %}"
+                           href="/about">
+                            <i class="bi bi-info-circle"></i> About
+                        </a>
                     </li>
                 </ul>
             </div>
@@ -41,6 +59,12 @@
         {% block content %}{% end %}
     </main>
 
+    <footer class="site-footer">
+        <div class="container">
+            &copy; 2026 Word Search
+        </div>
+    </footer>
+
     <script src="https://cdn.jsdelivr.net/npm/bootstrap@5.3.3/dist/js/bootstrap.bundle.min.js"
             integrity="sha384-YvpcrYf0tY3lHB60NNkmXc5s9fDVZLESaAA55NDzOxhy9GkcIdslK1eN7N6jIeHz"
             crossorigin="anonymous"></script>
diff --git a/templates/game.html b/templates/game.html
index edb3b39..2b38c8e 100644
--- a/templates/game.html
+++ b/templates/game.html
@@ -11,18 +11,25 @@
     <div class="card">
         <div class="card-body">
             <div class="row g-3 align-items-end">
-                <div class="col-md-4">
+                <div class="col-md-3">
                     <label for="category-select" class="form-label">Category</label>
                     <select id="category-select" class="form-select"></select>
                 </div>
-                <div class="col-md-4">
+                <div class="col-md-3">
                     <label for="board-size" class="form-label">
                         Board Size: <span id="size-display">10</span>
                     </label>
                     <input type="range" id="board-size" class="form-range"
                            min="8" max="20" value="10">
                 </div>
-                <div class="col-md-4">
+                <div class="col-md-3">
+                    <label for="word-count" class="form-label">
+                        Word Count: <span id="word-count-display">8</span>
+                    </label>
+                    <input type="range" id="word-count" class="form-range"
+                           min="3" max="30" value="8">
+                </div>
+                <div class="col-md-3">
                     <button id="new-game-btn" class="btn btn-accent btn-lg w-100">
                         Start Game
                     </button>
@@ -74,12 +81,6 @@
                                 Submit
                             </button>
                         </div>
-                        <div class="col-auto">
-                            <button id="submit-selection-btn"
-                                    class="btn btn-outline-light d-none">
-                                Submit Selection
-                            </button>
-                        </div>
                         <div class="col-auto">
                             <button id="clear-selection-btn"
                                     class="btn btn-outline-secondary d-none">
diff --git a/templates/howtoplay.html b/templates/howtoplay.html
index 83126e3..9675a29 100644
--- a/templates/howtoplay.html
+++ b/templates/howtoplay.html
@@ -1,8 +1,80 @@
 {% extends "base.html" %}
 
+{% block active_page %}{% set active_page = "howtoplay" %}{% end %}
+
 {% block title %}Word Search — How to Play{% end %}
 
 {% block content %}
-<h2>How to Play</h2>
-<p>Instructions coming soon.</p>
+<h2 class="mb-4">📖 How to Play</h2>
+
+<div class="content-section">
+    <h3 class="mb-4">Step-by-Step Instructions</h3>
+
+    <div class="step-item">
+        <span class="step-number">1</span>
+        <p>
+            📋 <strong>Check the word list</strong> — Look at the list of words
+            displayed alongside the grid. These are the words you need to find.
+        </p>
+    </div>
+
+    <div class="step-item">
+        <span class="step-number">2</span>
+        <p>
+            🔍 <strong>Scan for the first letter</strong> — Pick a word from the
+            list and scan the grid for its first letter. This gives you a starting
+            point.
+        </p>
+    </div>
+
+    <div class="step-item">
+        <span class="step-number">3</span>
+        <p>
+            ↗️ <strong>Look in all directions</strong> — Words can run
+            horizontally, vertically, or diagonally — and they can go forward or
+            backward. Check all eight directions from your starting letter.
+        </p>
+    </div>
+
+    <div class="step-item">
+        <span class="step-number">4</span>
+        <p>
+            👆 <strong>Select the word</strong> — Click or tap the first letter of
+            the word, then click the last letter to highlight the entire word.
+        </p>
+    </div>
+
+    <div class="step-item">
+        <span class="step-number">5</span>
+        <p>
+            ✅ <strong>Words get crossed off</strong> — When you correctly find a
+            word, it gets crossed off the list so you can track your progress.
+        </p>
+    </div>
+
+    <div class="step-item">
+        <span class="step-number">6</span>
+        <p>
+            🏆 <strong>Find them all to win!</strong> — The puzzle is complete when
+            every word on the list has been found. Try to beat your best time!
+        </p>
+    </div>
+</div>
+
+<h3 class="mb-3">💡 Tips</h3>
+
+<div class="tip-card">
+    <strong>Start with uncommon letters</strong> — Letters like Q, X, Z, and J
+    appear less often in the grid, making words with those letters easier to spot.
+</div>
+
+<div class="tip-card">
+    <strong>Scan systematically</strong> — Work through the grid row by row or
+    column by column rather than jumping around randomly.
+</div>
+
+<div class="tip-card">
+    <strong>Look for word shapes</strong> — Sometimes you can spot diagonal words
+    by the distinctive slanted pattern they make in the grid.
+</div>
 {% end %}
diff --git a/templates/main.html b/templates/main.html
index 1a09a71..10200b2 100644
--- a/templates/main.html
+++ b/templates/main.html
@@ -1,14 +1,17 @@
 {% extends "base.html" %}
 
+{% block active_page %}{% set active_page = "home" %}{% end %}
+
 {% block title %}Word Search — Home{% end %}
 
 {% block content %}
-<div class="text-center py-5">
+<header class="hero">
+    <div class="hero-emoji">🧩</div>
     <h1 class="display-4 fw-bold mb-3">Word Search</h1>
     <p class="lead mb-4">
         Find hidden words in a grid of letters. Words can appear horizontally,
         vertically, or diagonally. How fast can you find them all?
     </p>
-    <a href="/game" class="btn btn-accent btn-lg px-5">Start Game</a>
-</div>
+    <a href="/game" class="btn btn-accent btn-lg px-5">🎮 Start Game</a>
+</header>
 {% end %}
diff --git a/tests/conftest.py b/tests/conftest.py
index 80ae72d..37a35a3 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -23,6 +23,13 @@ def db_session(db_engine):
     session.close()
 
 
+@pytest.fixture(autouse=True)
+def clear_rate_limits():
+    from handlers.api import _rate_buckets
+
+    _rate_buckets.clear()
+
+
 @pytest.fixture
 def app(db_engine):
     from app import make_app
diff --git a/tests/e2e/test_api.py b/tests/e2e/test_api.py
index 39da19f..07071b9 100644
--- a/tests/e2e/test_api.py
+++ b/tests/e2e/test_api.py
@@ -110,3 +110,151 @@ async def test_text_guess_incorrect(http_server_client, seeded_db):
     assert resp.code == 200
     data = json.loads(resp.body)
     assert data["correct"] is False
+
+
+async def test_new_game_invalid_json(http_server_client, seeded_db):
+    resp = await http_server_client.fetch(
+        "/api/game/new",
+        method="POST",
+        body="not json",
+        headers={"Content-Type": "application/json"},
+        raise_error=False,
+    )
+    assert resp.code == 400
+    data = json.loads(resp.body)
+    assert "error" in data
+
+
+async def test_new_game_missing_category_id(http_server_client, seeded_db):
+    body = json.dumps({"board_size": 10})
+    resp = await http_server_client.fetch(
+        "/api/game/new",
+        method="POST",
+        body=body,
+        headers={"Content-Type": "application/json"},
+        raise_error=False,
+    )
+    assert resp.code == 400
+    data = json.loads(resp.body)
+    assert "error" in data
+
+
+async def test_new_game_string_board_size(http_server_client, seeded_db):
+    body = json.dumps({"category_id": seeded_db.id, "board_size": "big"})
+    resp = await http_server_client.fetch(
+        "/api/game/new",
+        method="POST",
+        body=body,
+        headers={"Content-Type": "application/json"},
+        raise_error=False,
+    )
+    assert resp.code == 400
+    data = json.loads(resp.body)
+    assert "error" in data
+
+
+async def test_new_game_custom_word_count(http_server_client, seeded_db):
+    body = json.dumps({"category_id": seeded_db.id, "board_size": 10, "word_count": 4})
+    resp = await http_server_client.fetch(
+        "/api/game/new",
+        method="POST",
+        body=body,
+        headers={"Content-Type": "application/json"},
+    )
+    assert resp.code == 200
+    data = json.loads(resp.body)
+    assert len(data["words"]) <= 4
+
+
+async def test_new_game_string_word_count(http_server_client, seeded_db):
+    body = json.dumps({"category_id": seeded_db.id, "word_count": "many"})
+    resp = await http_server_client.fetch(
+        "/api/game/new",
+        method="POST",
+        body=body,
+        headers={"Content-Type": "application/json"},
+        raise_error=False,
+    )
+    assert resp.code == 400
+    data = json.loads(resp.body)
+    assert "error" in data
+
+
+async def test_new_game_nonexistent_category(http_server_client, seeded_db):
+    body = json.dumps({"category_id": 99999})
+    resp = await http_server_client.fetch(
+        "/api/game/new",
+        method="POST",
+        body=body,
+        headers={"Content-Type": "application/json"},
+        raise_error=False,
+    )
+    assert resp.code == 404
+    data = json.loads(resp.body)
+    assert "error" in data
+
+
+async def test_guess_invalid_json(http_server_client, seeded_db):
+    body = json.dumps({"category_id": seeded_db.id})
+    create_resp = await http_server_client.fetch(
+        "/api/game/new",
+        method="POST",
+        body=body,
+        headers={"Content-Type": "application/json"},
+    )
+    game_id = json.loads(create_resp.body)["id"]
+
+    resp = await http_server_client.fetch(
+        f"/api/game/{game_id}/guess",
+        method="POST",
+        body="not json",
+        headers={"Content-Type": "application/json"},
+        raise_error=False,
+    )
+    assert resp.code == 400
+    data = json.loads(resp.body)
+    assert "error" in data
+
+
+async def test_guess_non_string_word(http_server_client, seeded_db):
+    body = json.dumps({"category_id": seeded_db.id})
+    create_resp = await http_server_client.fetch(
+        "/api/game/new",
+        method="POST",
+        body=body,
+        headers={"Content-Type": "application/json"},
+    )
+    game_id = json.loads(create_resp.body)["id"]
+
+    guess_body = json.dumps({"word": 12345})
+    resp = await http_server_client.fetch(
+        f"/api/game/{game_id}/guess",
+        method="POST",
+        body=guess_body,
+        headers={"Content-Type": "application/json"},
+    )
+    assert resp.code == 200
+    data = json.loads(resp.body)
+    assert data["correct"] is False
+
+
+async def test_guess_cells_with_null_element(http_server_client, seeded_db):
+    body = json.dumps({"category_id": seeded_db.id})
+    create_resp = await http_server_client.fetch(
+        "/api/game/new",
+        method="POST",
+        body=body,
+        headers={"Content-Type": "application/json"},
+    )
+    game_id = json.loads(create_resp.body)["id"]
+
+    guess_body = json.dumps({"cells": [None, {"row": 0, "col": 0}]})
+    resp = await http_server_client.fetch(
+        f"/api/game/{game_id}/guess",
+        method="POST",
+        body=guess_body,
+        headers={"Content-Type": "application/json"},
+    )
+    assert resp.code == 200
+    data = json.loads(resp.body)
+    assert data["correct"] is False