Cassette Beasts is a masterpiece of a monster collector game, rivalling if not even surpassing Pokémon at its best, because while it is obvious that Cassette Beasts is inspired by Pokémon, it utilises various aspects of Pokémon games with its own unique takes that are sometimes even better than Pokémon, from monster collecting mechanic, battle system, elemental type match ups, story, characters, lore, world building, map design, etc, with an amazing soundtrack that goes along with the game. As a result, Cassette Beasts is perfectly capable of standing on its own.
I cannot recommend Cassette Beasts enough if you like monster-collecting games, including, if not especially, if you like Pokémon but want an indie alternative, or something different after finding Pokémon games getting stale or becoming jaded by the direction of the Pokémon games.
+ +If you need more convincing on how Cassette Beasts is much more than a Pokémon clone, I have written a huge essay on this shrine.