What a nice experience. I love the calm and relaxing soundtrack and I think it really fits the minimalistic but very well executed pixel artwork. Together these two elements create a very interesting atmosphere. It's been mentioned in other comments but it is a bit difficult to aim enemies while trying to evade attacks, probably because both player and enemie have to be at the same height to hit one another and the fire ratio makes it easy for both shoots to be fired at the same time. However, the abundancy of checkpoints really helps and with a bit of practice, it gets easier. Great work!