CryptoKitties is a blockchain-based game that allows players to collect, breed, and trade virtual cats. Each cat is a unique digital asset represented as a non-fungible token (NFT) on the Ethereum blockchain. Players can create new cats by combining traits from their existing ones, leading to a variety of appearances and characteristics. Launched in late 2017, CryptoKitties gained popularity for its innovative use of blockchain technology in gaming. The game sparked interest in NFTs and contributed to the broader understanding of digital ownership. Players can buy, sell, and trade their cats in a marketplace, making it a unique blend of gaming and investment.