Nice. It was fun to explore.
I found sometimes the character would move to the next screen but the camera wouldn't follow so I was stuck looking at an empty room! This twice happened after I'd gone into a new room and seen spikes right in front of me so I quickly backed-off but then accidentally went back into the first room, so I went straight back into the spikes room the camera wouldn't follow. Maybe it's something to do with two room transitions in quick succession.
Having the projectile speed a lot higher from the outset would be good.