CryptoCosmos is described as 'allows players to collect and trade planets, from a database of every confirmed planet and exoplanet in the known universe. All 4380 minted as digital collectable NFTs on the ethereum blockchain' and is an app in the Bitcoin & Cryptocurrency category. There are three alternatives to CryptoCosmos for Online / Web-based and Ethereum. The best alternative is OpenSea, which is free. Other great apps like CryptoCosmos are Trusting Trust (Free) and CryptoKitties (Paid).
CryptoKitties is a game centered around breedable, collectible, and oh-so-adorable creatures we call CryptoKitties! Each cat is one-of-a-kind and 100% owned by you; it cannot be replicated, taken away, or destroyed.