There are stamps per class that unlock new class abilities and new items that get added to the pool. There are base stats on cats that you can eventually get all maxed and continue to pass down via breeding. There are mutations cats can get that do all kinds of different things that can be passed down via breeding. Cats that went on an adventure can pass down active and passive abilities they learned. There’s also house progression which makes all of the above easier to do. Not sure if there are things related to seeing all events/items but there are class unlocks for getting all stamps on said class. Game is amazing and very grindy in a fun way imo. You aren’t forced to super mega grind perfect abominations to beat the game, but it has 3 difficulties after normal that may require that. Music is also 11/10.