Nice game
I really enjoyed playing it, the art is amazing, and the music fitted extremely well :3. But I felt it was too short, the boss fight was nice but too easy, constantly sending flying the boss streched it a lot, I just had to stay in a single place and press A repeatly when the boss gets close then wait till he stops bouncing from the impact and repeat.
For some reason I can't double jump in the first lvls of hard mode, at first I thought it was disabled for more difficulty so I managed to get past the first and other 3 lvls with the jump+attack and then it suddenly started working ^^. I dunno if this just happened to me so I will give it 5/5 10/10 :P