Almost awesome.
Sweet game man. It was good, but not awesome, you know? There were some things holding it back, but most are minor and can be fixed in the few days you have left.
Like everyone's said, you have to upgrade the graphics, man. Heck, use the built-in Flash components if you have to. If you can find a Photoshopper, make him/her get you some grunge-based graphics.
Graphics would be easy to replace because, well... all you have to do is replace.
The second thing that could be fixed in a short period of time is the loading song screen. I never know when the song is going to start, so I'm sitting here, staring at the screen. Either a percentage thing or a load bar would be nice. Or a "ROCK ON DUDE" to say "GET OFF FACEBOOK AND PLAY FLASH HERO NOW".
These aren't so easily fixed. Perhaps in a sequel? =)
Six buttons is overkill man. Six would be hard enough on the GH controller, and that has a small fretboard. It has a small fretboard because Harmonix knows that some people have small hands. Not everyone has the hand length to move to the 6 key and back across without seriously injuring their wrist.
On a side note, a liability disclaimer might do you some good.
Anyways. I think 5 keys would be good. And maybe moving it to ~ through 4? I don't know if ~/` has a key code... I think it does. o.O I dunno. Maybe enable trapallkeys? Ah. Wait. If you used trapallkeys, then couldn't you use the function keys as frets? That would be lots better.
There's something else I wanted to gripe about. But I can't remember.
Love the game man. The song list is freaking huge! "MORE SONGS?!"