Mew-Genics is all about the game's "cast of cats," in that it features over 12,207,031,250,000,000,000,000 felines. The developer blog explains that the enormous number "only applies to how the cat looks, if you include its personality variables that number multiplies by A LOT."
Team Meat added that "ability variables and personal stats" could practically guarantee that you'll never get the same cat twice in the game. Not that we know what that entails, since all we really know about Mew-Genics is that it's "kind of" about cats. Lots of them.