You said you were going for 'frustrating' game-play, and that is very well executed in the main mechanic and the level-design, however the controls felt a bit 'slidy'? I don't know how else to describe it haha, so it felt like I was battling with the controls of the game for a lot of the time, which sure, is also frustrating, but I think the bad kind of frustrating, where it is out of your control.
I think with how the level design is set up, you can definitly tweak the controls a bit in order to make the game feel a lot better to play while still keeping the rage/annoyance inducing factor of the game!