I am using the keyboard, and I mean the final boss overall. Especially when I need to guide the rook from one side to the other. When the rock falls, the Fact attack makes it bounce, but the bounce is unreliable. And when I manage to get it to the side, the boss is already leaving to the corner and I can't get it to bounce high enough to hit it.
The rest of the game, no problem and I had a lot of fun.