From Games to DeFi, Here’s a Look at the Top 10 Winning Projects from the ETHGlobal NYC Hackathon

Rivals: An AR-based multiplayer shooter where players battle zombies in real-world environments using their phones, earning RIVAL tokens for kills. The game integrates blockchain and supports cross-chain token economics with Flow and Chiliz.
Primer: A Chrome extension enabling cryptocurrency payments on Amazon via gift card conversion. Users can pay with stablecoins like USDC, integrating wallets like MetaMask and Coinbase Wallet for seamless transactions.
Swap Pay: A payment SDK allowing users to pay with multiple tokens from their wallet without converting to a single token. Uses Chainlink for real-time valuations and EIP-5792 for streamlined transactions, settling in PYUSD.
Pumpkin Spice Latte: A DeFi savings app combining yield farming with a lottery. Users deposit stablecoins into a shared pool, with earnings pooled for periodic prize draws, ensuring principal safety while offering excess returns to winners.
Hardhat 3-Ledger: Integrates Ledger hardware wallet support into the Hardhat development framework, enabling secure smart contract deployments without exposing private keys. Includes TypeScript support and tested on Ledger Flex.
Noah: A digital asset inheritance solution using smart contracts for automated transfers after user inactivity. Supports multiple liquidation methods, ENS domain inheritance, and converts assets to fiat via Fern service.
Kyma Pay: Merchant-focused stablecoin payment infrastructure with a 0.15% fee, supporting PYUSD, USDC, and others. Uses an AMM for efficient swaps and includes risk assessment features for stablecoin reliability.
TX Delay Insurance: Offers insurance for EVM network transaction delays, compensating users if transactions are delayed due to congestion. Uses RPC proxy for timestamp verification, ideal for DeFi and arbitrage.
x402-flash: Optimizes x402 micropayment latency by using escrow contracts for immediate API responses. Reduces latency to milliseconds, supports USDC for gas, and integrates Circle Paymaster.
Pika Vault: Cross-chain asset management vault allowing deposits/withdrawals on any supported chain while rebalancing portfolios. Uses native USDC and Circle CCTP, with LayerZero and Chainlink CCIP for coordination and pricing.

The weekend-long ETHGlobal New York 2025 hackathon has officially concluded. As one of the world's leading Web3 developer events, the hackathon attracted numerous developer teams to explore new application scenarios for blockchain technology. After judging, ten projects were awarded prizes, covering a variety of areas including gaming, payments, DeFi, and development tools.

ETHGlobal New York provided a platform for developers to experiment with Web 3 technologies. Participants were able to develop innovative projects, learn new technologies, expand their professional networks, and connect with their peers. During the event, developers leveraged various blockchain protocols and tools to build projects covering multiple use cases.

Odaily participated in ETHGlobal New York and will introduce the winning projects below.

Rivals: Augmented Reality Shooter

Rivals is a multiplayer shooter that combines AR technology with a blockchain economy. Players use their phones to battle AI-controlled zombies in a real-world environment. Killing zombies rewards players with RIVAL tokens, while death deducts a portion of their token balance. The game uses Unity AR Foundation for environmental awareness, allowing virtual zombies to navigate and interact in the player's physical space.

The game includes a geo-trap system, allowing players to set traps at specific GPS coordinates that affect other players. The project supports multiple blockchain networks, including Flow and Chiliz, and utilizes a cross-chain token economic model. This design combines location-based services, augmented reality technology, and cryptocurrency incentives to create a new mobile gaming experience.

Primer: A cryptocurrency payment method for shopping

Primer is a Chrome browser extension that allows users to use cryptocurrency for purchases on Amazon. Since Amazon doesn't directly support digital asset payments, the extension uses gift cards as an intermediary to facilitate payment conversion. Users click the embedded "Crypto Checkout" button to complete payment using stablecoins like USDC.

The system automatically converts cryptocurrency into Amazon gift cards and applies them to orders in a transparent process. The extension integrates with major wallets like Coinbase Wallet, MetaMask, and Phantom, using the Coinbase CDP API for transaction verification. This approach bypasses the limitations of traditional e-commerce platforms that don't support cryptocurrencies, providing digital asset holders with a new consumption channel.

Swap Pay: Multi-token Combination Payment

Swap Pay addresses the token compatibility issue in Web 3 payments. The SDK allows users to pay using a combination of tokens in their wallets, without having to convert them to a single merchant-specified token. The system uses Chainlink data sources to provide real-time token valuations, allowing users to select the number of different tokens needed to make up the payment.

Through the EIP-5792 standard, all authorization, redemption, and transfer operations are bundled into a single transaction, streamlining the payment process. Final settlement uses PYUSD, and if the total value of the user's selected tokens exceeds the required amount, the system automatically refunds the difference. This design reduces operational complexity in Web3 commerce and allows decentralized token balances to be used more efficiently for payments.

Pumpkin Spice Latte: A Rewarding Savings App

Pumpkin Spice Latte combines DeFi yields with a lottery mechanism to create a new savings incentive model. Users deposit stablecoins into a shared pool, keeping their principal safe. All deposited earnings are pooled for regular prize draws. Winners receive excess returns, while those who don't win retain their entire principal.

The project supports ERC 4626-compliant yield sources, including DeFi protocols like Morpho and Kinetic. Random number generation uses Flare and Flow's VRF services to ensure fairness. This model aims to make savings more attractive while providing users with a way to participate without risking their principal.

Hardhat 3-Ledger: Hardware Wallet Development Integration

Hardhat 3-Ledger adds support for Ledger hardware wallets to the latest version of the Hardhat development framework. Developers can use Ledger devices to securely sign smart contract deployment transactions, avoiding exposing private keys in the development environment. It integrates with Ledger's device management toolkit, supports TypeScript, and has been tested on Ledger Flex devices.

The project team also provided suggestions for improvements to the Ledger developer documentation, including code example optimization and document structure adjustments. This integration is valuable for blockchain projects requiring high security standards, allowing developers to use modern development tools while maintaining security.

Noah: Digital Asset Inheritance Plan

Noah provides a digital asset inheritance solution that automates inheritance transfers through smart contracts. The system uses a "dead man's switch" mechanism, automatically transferring assets to designated beneficiaries if a user is inactive for a set period of time. The project supports multiple liquidation methods, including Dutch auctions and Uniswap transactions.

The system can convert digital assets into USDC or PYUSD, or directly into US dollars through the Fern service. For users who choose to withdraw in fiat currency, beneficiaries can inherit their assets without even having to understand cryptocurrency. Noah also supports ENS domain name inheritance and has been deployed on multiple blockchain networks, including Flow, Chiliz, and Katana.

Kyma Pay: Stablecoin Payment Infrastructure for Merchants

Kyma Pay provides merchants with GENIUS Act-compliant stablecoin payment processing services with a 0.15% fee, significantly lower than the 1.5% fees charged by traditional payment providers like Stripe. The system supports major stablecoins such as PYUSD, USDC, USDT, and USDDe, utilizing an AMM designed based on Orbital to enable efficient stablecoin swaps.

The project integrates the HTTP 402 payment protocol. When a customer attempts a purchase, a 402 status code is returned with payment information. The Coinbase x 402 Facilitator handles payment verification. The system also includes a stablecoin risk assessment feature, providing merchants with a risk score based on data such as reserve assets and audit history. This design aims to provide merchants with a more economical digital currency payment option.

TX Delay Insurance: Transaction Delay Insurance

TX Delay Insurance provides insurance against transaction delays on the EVM network. Users can purchase insurance for time-sensitive transactions and receive financial compensation if their transactions are delayed due to network congestion. The system records transaction broadcast and execution timestamps via an RPC proxy as proof of delay.

Insurance contracts allow users to purchase delay protection for specific transactions, with claims based on verifiable timestamp data. This mechanism is valuable for time-sensitive scenarios like DeFi operations and arbitrage trading, providing users with a tool to combat network uncertainty.

x 402-flash: Micropayment latency optimization

x402-flash addresses the latency issues inherent in the x402 micropayment standard through an escrow contract system. While traditional x402 requires blockchain transaction confirmation before responding to API requests, the flash solution allows clients to pre-lock funds in an escrow contract, enabling the server to respond immediately, accelerating the payment process through micro-insurance.

Actual payments are processed asynchronously in the background. If the client's balance is insufficient, the escrow contract automatically deducts the pre-deposited funds. This design reduces payment latency from 200 milliseconds to double-digit milliseconds, enabling high-frequency API calls. The project integrates Circle Paymaster and supports USDC for gas fees, streamlining the user experience.

Pika Vault: A cross-chain asset management vault

Pika Vault enables cross-chain asset management, allowing users to deposit and withdraw assets on any supported blockchain, while the vault maintains and rebalances portfolios across multiple chains. The system is based on the ERC-4626 standard and supports ERC-7540 asynchronous redemptions. Unlike solutions that rely on synthetic assets or complex bridges, Pika Vault uses native USDC and Circle CCTP for cross-chain transfers.

The architecture separates the control plane and the value plane, with LayerZero handling cross-chain coordination and Chainlink CCIP providing price data. The system supports qualified custodial addresses, meeting the regulatory requirements of institutional investors. This design enables true cross-chain asset management, avoiding the limitations of a single chain and the risks of synthetic assets.