Yeah, I know, that the penalty is disturbing, but it needed a challenge and I thought, this was one. ;) During the development I also had a version, where even a hit to the ceiling during a jump, would give you this penalty. But I removed it.
I will improve it in the next version (but it might not get removed).
Of course the graphics are terrible. But this will definetly change. :) There will be be backgrounds, I really want to make it look like a beautiful C64 or Amiga-Game. That would fit the gameplay the most, I think.