Monster Collecting RPGs!

I recently looked up what kind of systems there are for monster collecting type games in the rpg space and there honestly wasn't much (though maybe I just didn't look far enough)! Most of the systems I did stumble across were pretty rules heavy, which I guess does come with the material to some extent.

While most of the rpgs were simply monster collecting hacks for already existing systems, totally unique games like Animon Story did feel pretty cool, but I had never heard of them before explicitly searching for it, which kind of surprised me, since monster collecting video games like Pokemon are such a big thing.

Have you played in / GMed for any monster collecting games? Do you have game recommendations? What are some things you like or dislike about the concept? Do you think the concept has potential in a pen & paper space or is simply not that great of a fit?

Ah and finally, I did make a Persona-esque rpg at one point and I'd love to cross-reference some mechanics with other games, so if you have any game recommendations or thoughts that go in that sort of direction, I'd be really thankful!