I agree that the first jump was a bit too tough (I think it was the hardest one in the game for me...) and also thought that maybe there were a bit too many deadly spikes. I liked the difficulty, but just a little breathing room after beating a miniboss would've been appreciated (I almost flew into some spikes right after exiting the boss room). I liked the enemy variety and the animation of the player character is super nice. I also thought the music complimented the overall style really well.
I thought it was really fun and I was pleasantly surprised by how cohesive and complete it felt :) nice job!