I don't think the game is too difficult, I'm clearly not the best at those kind of things and I finished it, it was just challenging enough. But the doors bugs, I gets regularly stuck in the door, can't go out and can't moove. In one level (the one with like five falling blocks and two other falling from the sky), the floor under the door got no hitbox in almost all my runs, I was just falling through.
That being said, I realy liked your game :)