Seizures and high blood pressure
I'll give you a 10 for the first half, which was a legitimately well-made platform game with great ideas. The second half is, well, sadistic; an exercise in patience and perfection which ends up in failed anger management. Not the kind of game I like to play. So I simply stopped at Hard 4.
@Herbie2606 Yeah that's the "last" level. Might as well finish it for accomplishment's sake.