Reminiscent of Tamagotchi and Pokémon, the wildly popular digital pets and creatures of the 1990s, CryptoKitties is a blockchain-based game where players can collect, trade and breed digital virtual cats. CryptoKitties was the first Ethereum-based game, and its popularity underscored many of the network’s scaling issues.
This digital cat-breeding blockchain game caused quite a bit of congestion on the Ethereum blockchain, peaking in 2020. However, the game’s creators were able to address these issues.