This is a good effort. Little things like the level wipes are nice touches. The level design for a platformer is decent, and quite challenging. The graphics and sound/music is appropriate. Keep up the good work!
btw, there is a bug on one of the levels where you need to jump on an enemy to avoid the spikes because if you hit the spikes after killing the enemy, the "try again" doesn't reload that character making it impossible to finish the level.