Nice game! It is quite hard, as you said, and sometimes you can fall all the way to the bottom.
The music really helps create a nice ambience, and the pixel art graphics is nice.
As for the input, I think the player should be more centered, to allow for more mouse movement. And it seems that only clicks near the player are accepted, ignoring those that are too far. Sometimes the game didn't register the input because of that.
Overall, a nice game.