This was a nice game!
At one point, I clicked at the same moment he struck the mochi with the kine. This caused a game-over. I think it would be nice to have a very short invincibility timer after the player clicks again, if you don't have that already. It might just be me, though.
I also think it would be nice to have a more hectic game mode, where you introduce some new mechanics. But I understand that might not fit with your plans for the game.
Hope development goes well! :)