Build an AI-Powered Crossword Game with Google Gemini

On How to,

Crossword puzzles are one of the most effective interactive learning tools for knowledge retention—especially valuable for teachers and educational content creators. Instead of manually designing each grid and clue, you can now leverage AI to generate complete games in minutes.

In this guide, we'll use Gemini to build an AI Crossword Generator tool using HTML, CSS, and JavaScript. The tool accepts topic, difficulty level, word count, and language preferences, then automatically generates keyword lists, hint clues, and arranges them into a fully functional crossword grid.

How to Create an AI Crossword Game with Gemini

Important Note

Below are multiple prompts that build the crossword game step by step. Enter the first prompt to have Gemini design the interface, then continue adding subsequent commands in the same chat window without creating new conversations.

You'll construct the game within Gemini, then export it as a complete HTML crossword file.

Prompt 1: Build the Core AI Crossword Generator

You are a Web AI programmer and UI/UX Designer.

Create an "AI Crossword Generator" application using HTML, CSS, and Vanilla JavaScript in a single index.html file.

The application runs directly in Chrome without requiring a server.

OBJECTIVE:

Build a tool that lets users input a topic and automatically generates a crossword puzzle game.

---

INTERFACE DESIGN:

Use an Educational AI Game aesthetic.

Include:

- Title: AI Crossword Generator
- Decorative icons: books, pens, AI robot, globe, letters, lightbulb

The interface has these sections:

1. Input Area:

- Topic
- Difficulty Level:
  + Easy
  + Medium
  + Hard

- Word Count:
  + 5 - 30 words

- Language:
  + Vietnamese
  + English
  + Bilingual

- Additional Instructions

Include a button:

✨ Generate Crossword

---

2. AI-Generated Content:

When "Generate Crossword" is clicked:

AI automatically creates:

- List of keywords
- Clue hints
- Answers

ANSWER RULES:

- All answers in UPPERCASE
- No Vietnamese diacritical marks
- No spaces
- No special characters
- Letters A-Z only

Examples:

Correct:
CAHEO
CAMAP
MAYTINH

Incorrect:
CÁ HEO
CÁ MẬP
MÁY TÍNH

Clues remain in Vietnamese with full diacritical marks and clear wording.

Before creating the crossword grid:
- Auto-normalize answers
- Remove diacritical marks
- Remove spaces
- Use normalized answers for grid placement and verification

---

3. Crossword Engine:

Auto-generate the crossword grid.

Requirements:

- Words intersect logically
- Prioritize longer words first
- Optimize grid size
- Center automatically
- Number horizontal and vertical clues

---

4. Display Results:

After generation:

Show:

- Crossword grid centered
- List of horizontal/vertical clues
- List of AI-generated keywords

---

5. Edit Data

After AI creates the crossword, the system auto-generates:

- Keyword list
- Clues for each word

Display data in a table:

| # | Answer | Clue | Actions |

Each row contains:

- Number
- Answer (editable field)
- Clue (editable textarea)
- Save button
- Delete button

Requirements:

- AI auto-generates initial keywords and clues
- Users can edit answers if needed
- Users can edit AI-generated clue content
- Users can add or delete keywords
- Users can add or edit clues per their needs

When Save is clicked:

- If answer changes:
  → Auto-regenerate the crossword grid

- If only clues change:
  → Update question list only, no grid regeneration needed

When "Regenerate Crossword" is clicked:

- Use edited data
- Don't overwrite user-edited clues
- Only create new keywords and clues when user enters a new topic and clicks "Generate Crossword"

---

6. Data Management:

Create a centralized data source:

crosswordData

Store:

- topic
- level
- language
- words (answers without diacritics, no spaces)
- clues (clues in Vietnamese with full diacritical marks)
- grid
- game state

Data Rules:

- words: UPPERCASE only, no diacritics, no spaces
- clues: complete content with full diacritical marks

Example:

words:
MAYTINH

clues:
Thiết bị điện tử dùng để xử lý thông tin.

Each new topic:

- Delete all old crosswordData
- Generate new data
- Regenerate crossword grid
- Update entire interface

---

Technical Requirements:

- HTML5
- CSS3
- JavaScript ES6

No React, Vue, or Bootstrap.

Full working code.

If too long, split into Part 1, Part 2, Part 3.

Prompt 2: Add Direct Letter Input to Grid Cells

Upgrade the current Crossword game.

Keep the existing interface and crossword generation features.

Add interactive gameplay functionality only.

---

Players can:

- Click directly on grid cells
- Selected cell highlights
- Type letters using keyboard

When typing:

- Letter appears in cell
- Auto-advance to next cell

Support:

- Backspace:
  Delete current letter and return to previous cell

- Arrow Keys:
  Navigate between cells

---

Each cell manages:

{
row,
column,
correctLetter,
userLetter,
status
}

Status values:

- empty
- typing
- correct
- wrong

---

Answer Verification:

When a word is completed:

If correct:

- Cell turns green
- Display:
🎉 Correct!
- Add points
- Show clapping animation

If incorrect:

- Cell shakes slightly
- Turn red
- Display:
❌ Wrong, try again.

Allow user to retry.

---

Do not change current design.

Add only letter input logic and answer verification.

Prompt 3: Regenerate Game, Show Answers, Manage Data

Continue upgrading the current Crossword game.

Do not change the interface.

Add these features:

---

1. REGENERATE GAME FOR NEW TOPIC

Add button:

🔄 Regenerate Game

When user enters a new topic and generates:

Must delete all old data:

- Old crossword grid
- Old keywords
- Old clues
- Old answers
- Player-entered letters
- Score
- Game state

Then:

Generate completely new crossword for new topic.

Example:

Old:
Animals

New:
Fruits

No animal data remains.

---

2. SHOW ANSWERS BUTTON

Add button:

👀 Reveal Answer

When player gets stuck:

- Select a cell or clue
- Click reveal answer button

Show answer for that word only.

Example:

Clue:
Yellow curved fruit.

Reveals:

BANANA

Corresponding cells auto-fill.

Do not reveal entire grid.

---

3. EDIT DATA

Edit section must show numbering:

Example:

1.
Answer:
SEA LION

Clue:
Intelligent ocean mammal.

2.
Answer:
SHARK

Clue:
Predatory fish species.

Requirements:

- Auto-number
- New entries auto-increment
- Delete auto-updates numbers
- After editing, regenerate crossword

---

4. Data Flow:

When generating game:

resetGame()

↓

generateNewData()

↓

createCrossword()

↓

renderGrid()

↓

renderQuestions()

↓

renderWordList()

No old data retained.

Prompt 4: Complete the Game

Finalize the current Crossword game.

Add:

- Timer countdown
- Score system
- Completion progress bar
- Victory animation
- Confetti effect
- Correct/incorrect sounds
- Dark Mode
- localStorage data persistence

Add feature:

📤 Export Game as HTML

Exported file:

crossword-game.html

Requirements:

- Open directly in Chrome
- No server needed
- No API required
- Game-only version
- Keeps all questions, answers, grid, and effects

Do not break existing functionality.

After entering these four prompts sequentially, you'll have a complete crossword game. Simply input the topic, difficulty level, and word count, and Gemini will generate your crossword puzzle.