Hello there,
I just played this game for about 2 - 3 hours.
I like the idea of the trainer being in battle with the monster as well and I think the game is very polished and it doesn't feel like RPG maker game at all!
This game has a lot of potential, does this game get inspired by PS 1 game Jade Cocoon by any chance ? not sure if you are familiar with it, but you can merge monster there as well.
If you want some tips, I would probably add main quest log on the HUD or some sort of navigation on where to go to continue the story. Because at one point I had to afk and I forgot the dialogue and had no idea where to go.
But overall I think the game is pretty good !