very creative use of the limitation! the graphics are neat, they remind me of downwell
it's tough, but fair
though i would suggest maybe having it so the player can press R to reset the level instantly instead of having to wait for the ball to reach their goal, i think it would benefit from that a lot
the boss was also pretty well done, though it was a bit hard to understand how many hits you had to get in, maybe make the screen crack a little more than it does right now when you hit the first and second goals? so when you hit the second one there would be cracks all over it