Great!
Finally a good rythm game to Newgrounds :)
The graphics were great, and so were the songs.
This game was hard, but not impossible. For the people who complain about hitting 2 sides at the same time, try pressing those buttons at the same time? hold left and right at the same time to hit two sides.
I never got to the Insane level (yet!), but i did get to Hard. I noticed that in the end of the song, the monsters appeared to be a bit out of rythm: a bit too late, which made it very hard to hit them at the right time. It could be just me, but i think you should look into that.
Great game, great songs. Awesome, 5.