Haven't played much of it (haven't had much time, I beat one level and didn't get back to the start on the second one). But it seems to be pretty fun, and the music isn't boring (but still a bit repetitive). The sound effects seem to work well: I can tell when I'm taking damage.
Art comment: when the floor is made of of a bunch of identical tiles, the pattern in those tiles probably could probably be a bit more subtle. Those light and dark spots repeating over and over are a bit like the music. Well, at least the art and the music fit well together.