Flip9 - Multiplayer Memory Game

A multiplayer memory card game where players take turns flipping cards in numerical order from 1 to 9. The game allows two players to play together from different devices.

Features

• Real-time multiplayer gameplay without WebSockets
• Vercel-compatible implementation using Vercel KV as the datastore
• Share a link to invite friends to play
• Mobile-responsive design

How to Play

1. The first player creates a game and shares the link with a friend
2. The second player joins by clicking the link
3. Players take turns flipping cards, looking for numbers 1 through 9 in sequence
4. If a player flips an incorrect card, their turn ends, and they start again from 1
5. The first player to find 9 wins the game

Tech Stack

• Next.js 14 (App Router)
• TypeScript
• Tailwind CSS
• Vercel KV (for state management)
• SWR (for data fetching and polling)

Local Development

First, install dependencies:

npm install
# or
yarn

You'll need Vercel KV for the multiplayer functionality. You can use a local Redis instance for development:

1. Create a new Vercel project and add a KV database
2. Get your KV credentials from the Vercel Dashboard
3. Copy src/env.local.example to .env.local and add your KV credentials

Then run the development server:

npm run dev
# or
yarn dev

Visit http://localhost:3000 to play the game locally.

Deployment

The easiest way to deploy is with Vercel:

1. Push your code to a Git repository
2. Create a new project in Vercel and link it to your repository
3. Add your KV credentials to the Environment Variables in the Vercel dashboard
4. Deploy

How Multiplayer Works

This game uses a polling-based approach instead of WebSockets for Vercel compatibility:

1. Game state is stored in Vercel KV
2. Players poll for updates to the game state every 2 seconds
3. When a player makes a move, they update the game state in KV
4. The opponent receives the updated state on the next poll

This approach allows for near real-time gameplay without requiring WebSockets, making it compatible with Vercel's serverless architecture.

License

MIT