This was fun; I liked the gameplay, though some of the controls felt a bit janky to me. I also didn't really use the gravity switching almost ever, because I could solve everything by shooting things around.
Oh, yeah. I think I must have used the gravity switch there. I think there was one level (the one where it's introduced, or the one right after?) where I used it, but after that, I didn't get into a situation where it felt required.
