A 12-card memory matching game built on the Ethereum Sepolia testnet and deployable as a Telegram Mini App. Match shape pairs to mint real ERC-1155 NFTs to your wallet and earn $MEMORY tokens — all on-chain, tamper-proof, and completely free to play using testnet ETH.
- 12-card concentration game — 6 shape pairs in a 4×3 grid
- On-chain match verification — the smart contract validates every pair, not the frontend
- NFT minting — each matched pair mints a Shape NFT (Circle, Square, Triangle, Star, Heart, Diamond) to the player's wallet
- Play-to-earn simulation — earn 10
$MEMORYtokens per pair, 50 bonus tokens for winning - Two game modes — off-chain (no wallet, instant play) and on-chain (MetaMask, Sepolia)
- 2-player support — turn enforcement via contract state (
currentPlayermapping) - Telegram Mini App — runs natively inside Telegram via the Mini Apps SDK
- Fully free — uses Sepolia testnet; no real money involved
| Layer | Technology |
|---|---|
| Smart Contract | Solidity 0.8.20, ERC-1155 (OpenZeppelin) |
| Blockchain | Ethereum Sepolia Testnet |
| Frontend | Vanilla HTML5 / CSS3 / JavaScript |
| Web3 Library | ethers.js v6 |
| Deployment Tool | Hardhat v2 |
| Hosting | GitHub Pages |
| Wallet | MetaMask |
| Telegram Integration | Telegram Mini Apps SDK |
Off-chain mode (no wallet needed):
- Open the game and click New Game
- Click any card to flip it — it reveals a shape
- Click a second card to try to find the match
- If they match, both cards stay face-up and you score a pair
- If they don't match, both cards flip back — remember where they were!
- Find all 6 pairs to win
On-chain mode (MetaMask required):
- Open the game in a browser with MetaMask installed (served via HTTP, not
file://) - Click Connect Wallet and approve in MetaMask
- Make sure MetaMask is set to the Sepolia network
- Click Play On-Chain — confirm the transaction to create a game on-chain
- Play normally — each matched pair triggers a MetaMask confirmation to mint your NFT
- View your minted NFTs at testnets.opensea.io
Contract: MemoryGame.sol
Standard: ERC-1155 (multi-token: NFTs + fungible reward token)
Network: Ethereum Sepolia Testnet
| ID | Token | Type |
|---|---|---|
| 0 | $MEMORY |
Fungible reward token |
| 1 | Circle NFT | Shape pair NFT |
| 2 | Square NFT | Shape pair NFT |
| 3 | Triangle NFT | Shape pair NFT |
| 4 | Star NFT | Shape pair NFT |
| 5 | Heart NFT | Shape pair NFT |
| 6 | Diamond NFT | Shape pair NFT |
MIT — free to use, modify, and distribute.
Built with Solidity, HTML5, ethers.js v6, OpenZeppelin, Hardhat, and the Telegram Mini Apps SDK.