Cute game! Very good story and nice presentation. Making and animation 3D models for a game jam is very impressive.
I thought that puzzle variety was fine for its length. The only element I’m unsure about is the logs, because they were introduced rather late, but they had good levels regardless.
I agree with other commenters here that the puzzle gameplay could be improved. Movement and actions felt a little slow, sometimes Mokou’s attacks didn’t hit youkai, and visibility cones weren’t very clear. I think that with a dedicated 3D engine you could improve on all this and add nicer lighting too.
Overall nice job.