Some thoughts:
Not a fan of the first area. Especially the second and third screen felt really tedious.
Didn't like the first boss too much either. Only being able to hit him once per attack made the fight really drag out and didn't reward good play by being able to stay on the higher blocks.
Second area starts much better. I really like the way you use spike triggers and it plays pretty nicely.
^ Are you supposed to be able to save jump the bottom right jump? It's extremely tight without it.
And I don't think having the touch save troll at the end of the third (?) screen is a good idea. In general robbing players of their progress is an easy way to create unfun frustration