Nice game, though a bit difficult. As people mentioned before, making the hitbox of the pins would've been nice or some other sort of assist. Another thing you might consider adding is, that the pins could glow or have some sort of outline, as in the current game they are difficult to see. Another thing I'd love to see would maybe be some different kinds of keys or another type of challenge.
This game is really well made, Good Job!
(Also, it would be cool if you could play my game too! ^^)