MegaRally

Fluffle Dash v2: a mobile-first, Flappy-Bird-ish on-chain rally game.

• Players start one or more paid entries within a timed round.
• Each entry gives you up to 3 attempts.
• You dash in a canvas runner.
• Your distance is your score.
• Leaderboard uses your best entry.
• When the round ends, the top score wins the pool (minus a 2% fee).

Architecture

src/              Foundry — MegaRally.sol
test/             Foundry tests
script/           Deploy script
web/              Next.js 14 + wagmi v2 + viem (Canvas 2D gameplay)

Quickstart (local)

1) Start Anvil

anvil

2) Deploy contract

# Uses first Anvil default key
forge script script/Deploy.s.sol --rpc-url http://127.0.0.1:8545 --broadcast --private-key 0xac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80

Note the deployed address — if it's not 0x5FbDB2315678afecb367f032d93F642f64180aa3, update NEXT_PUBLIC_CONTRACT_ADDRESS in web/.env.local.

3) Run the frontend

cd web
cp .env.local.example .env.local   # edit if needed
npm install
npm run dev

Open http://localhost:3000, connect MetaMask (add Anvil network: RPC http://127.0.0.1:8545, Chain ID 31337), and import an Anvil test account.

4) Run tests

forge test -vvv

Demo mode (no wallet)

In web/.env.local set:

NEXT_PUBLIC_DEMO=1

This enables a local-only round with simulated opponents (no chain / wallet required).

Batching: why distance doesn’t mean “tap = tx”

Gameplay produces distance continuously, but on-chain writes are batched to keep transaction frequency sane.

Frontend behavior:

• Accumulates distance locally.
• Commits every ~3 seconds or when the local buffer exceeds a threshold.

Contract behavior:

• submitActions(roundId, amount) increments your score by amount in a single tx.

Contract API

Function	Description
createRound(entryFee, duration)	Create a new timed round
startEntry(roundId)	Start a new paid entry (payable, per entry)
joinRound(roundId)	Back-compat alias for startEntry
submitActions(roundId, amount)	Batch-submit distance/actions (recommended)
submitAction(roundId)	Legacy single action (calls submitActions(roundId, 1))
finalizeRound(roundId)	After round ends — pays winner 98%, feeReceiver 2%

MegaETH deployment

1. Set env vars:

   export NEXT_PUBLIC_CHAIN=megaeth
   export NEXT_PUBLIC_MEGAETH_RPC=https://rpc.megaeth.com
   export NEXT_PUBLIC_CONTRACT_ADDRESS=<deployed-address>

2. Deploy contract with MegaETH RPC and your deployer key.
3. Run the frontend.

License

MIT

Deployed testnet build via GitHub Pages (Actions).