I liked how you avoided making a runcycle for your character :)
Graphics are simple but fitting, yet music is missing :( every hardcore platformer needs a catchy tune in my opinion.
Maybe take a look at freesounds and stuff or ask a sound guy/girl to make sth cool for you (im one by myself, so I can tell you that most sound people love to get asked for such things).
However there was a level goal that didnt let me through so I assumed that I was finished.
The difficulty was perfect in my opinion.
Good game, thanks for making it