Hello!
I gave your game a try and got through the second world. The character art is nice and i enjoyed the music! There seemed to be several bugs through out and i think malerouille pointed them out already. There were three things that stood out to me that needed fixed. I would change when you fall on spikes. there is no invulnerability so you dont have a chance to get away. Also the enemy hit boxes were weird. I feel like i would get hurt even if i jumped on top of them. lastly, i think if you were able to jump on top of the bosses heads instead of just falling through them would be nice.
Good job and keep plugging away!