The controls are a bit unintuitive, so maybe if the jump was on <space>, it would improve the user experience a bit.
Yes, the game is quite difficult, I was only able to collect 4-5 leaves before falling. I'm also a little confused by the fact that the player probably needs to hit a small fox sprite accurately before getting a good ending, but maybe I'm wrong.
I had to use "cheats" to see the art for a good ending.