I agree with Btastic.
I'm also a huge fan of rhythm games, and I know what makes 'em good. The rhythm of the notes were really awkwardly placed, and rarely ever went with the beat. Some songs it didn't really recognize. Now, I know I'm repeating Btastic, but these are things that needed fixed. The GUI was perfectly fine with me, it's just that I like hitting my arrows to a beat, not some random bullcrap placed notes. An in-game key editor would be a good idea. I don't know why Btastic's review was thumbs-downed, I found it helpful so this could be made into what a rhythm game should really be. It might as well be considered a mashing game in it's current state.