CryptoKitties is an ethereum blockchain based virtual game developed by Axiom Zen that allows players to purchase, collect, breed, and sell various types of virtual cats. CryptoKitties are collected and breed based on their cattributes. The community around the game has developed a number of tools to understand and visualize the all the facets of the game.
Ethereum is a intricate part of CryptoKitties. In order to do anything with CryptoKitties you will first need to obtain an Ethereum wallet and address. MetaMask is a common solution for providing a web browsing experience that integrates with an Ethereum wallet. After this ether needs to be obtained, often by buying the cryptocurrency at an exchange.
Pretty much the first action a player does in CryptoKitties is buy their first kitty. After that, players can decide on their own style of play. Some players, simply buying and selling. However, the main gameplay of CryptoKitties centers around breeding in order to breed a unique kitty such as a Fancy or to obtain a mewtation. When players don't want to do any of these options they can just CUDL, and keep their collecting waiting till they wish to return.
CryptoKitties are used in a number of other ways. Players can directly trade their kitties or using a middle-man service. OpSkins allows CryptoKitties to be used on their platform. Other games such as KittyRace use the CryptoKitties tokens in non-standard ways by building a game around the tokens.
In addition to the CryptoKitties with SVG artwork, there are unique kitties that have genetic recipe which then renders a unique and limited edition kitty called a fancy. Even more rare than a fancy kitty is an exclusive kitty. Exclusive kitties are only awards and can only be breed in the sense that sometimes a specific numbered kitty will be an exclusive (e.g. Cathena).