Holy smokes! Dynamically generated rhythm game where you can use your own songs! Reminds me of "Audiosurf" in that regard. This is a lot of fun to play. Great job, impressive scope for a jam! :)
Everyone is giving their two cents in regards to the "depth" issue. Here's my idea: maybe have the squares and your cursor produce "drop shadows" on the ground beneath? That way the bottom will almost look like a guitar hero lane to help with timing. Personally I didn't find the depth issue that bad though. It is a rhythm game: you are supposed to press it to the beat! I'm sure this could be more of an issue on harder difficulties though.