Pokete is a good game and it's fun
I played another FLOSS Pokemon game, it had graphics. I don't know if it was Tuxemon (Edit: I looked it up and I'm pretty sure it is Tuxemon). There was only a long intro story, no fighting at all.
Note that Pigeon Ascent has all the mechanics of a Pokemon game but is limited to mutant pigeons. It has graphics. It could be turned into a full-scale monster game. It is written using Godot so it only runs in my browser, not native (for me).