In terms of colour harmony and the graphics assisting the gameplay, this is my favourite game so far. As others said, it would have been even better with sound. I think some camera shake and a message upon death would make it even better because I don't even realize I'm dead until a bit of time has passed. I loved the bullet graze mechanic, too.
I was going to say it doesn't follow the limitation well but then I read your "use of the limitation" part. The bomb placement doesn't seem to coincide with the positions of the reflections, though, which feels unfair (why should I avoid the mirror pieces if bombs are going to be all over the map anyway?).