I had a lot of fun with this demo and I think this game seems pretty promising. I like the premise of the world and the monster designs are neat.
I had one problem where dialogue options were going off the side of the screen.
Other than that I feel like monster fusion should show you the result before you fuse since you can just savescum it anyway, and it would be nice if there was a way to know what type an attack was at a glance without having to read it's description.