I breezed through the first 3, the last one is a bit more challenging, but after some tries, I was able to complete it in full. I tried hard mode, but it was a bit too unforgiving. Other than that, I liked this, nice little story too.
EDIT: Okay, so I might be stupid, because I just found out about the powerups AFTER the fact. So I was just rawdogging it this whole time