Hm, very good game. Best thing about it is, some songs that aren't difficult at all on Audiosurf, can still be difficult in this game. The opposite also holds true; while I can't even dream of getting stealth on 'Ou Mono' from the Paprika OST on Audiosurf, I got an easy 100% on fast with it here.
I noticed a huge difference in particular with Ali Project's songs. I also found that "Motteke Sailor Fuku Metabo Taisku Mix" was rather difficult.
Most important feature it needs is being able to play full songs, of course >.> An online scoreboard like Audiosurf's would also be very nice.
I would also like to compliment the game's creator on adding a couple of functions that Audiosurf lacks; most notably the fact that it previews songs while choosing them, and the fact that it keeps track of your highest score so far on the song.
Good job, can't wait until 1.0.