Neat development. The overall game is pretty good, even if quite short. I think that the jump is a bit too high and "floaty" feeling. The run animation looks great, really amazing. Nice enemies and boss variety as well. I really like however you did the save/checkpoint system. Player character sounds would be good. Great start, just needs more time and work put in; great work for 9 days! Loved the boss fight too, there is actually some strategy involved!