The game is very frustrating in a way I don’t know if it was intended or not. I beat all the levels though.
The final jump on stage 3 is too high and doesn’t work most of the time. The cannons just change their speed every shot? So they will shoot a slow shot and follow it up with a fast one and you will get hit by both because the player has no invulnerability frames where they get to move. The sound effects are too loud compared to the music and there is no way to adjust them.
I feel like the difficulty never actually comes from the main growth mechanic, just the curve of the jump, the ceilings spiking you downwards on impact and the cannons calculating the perfect shot speeds to combo you for all your lives.