At the 'Main' menu go to 'Options' and then 'Cheats' and select 'Enter New Cheat' and enter the following codes (each combination of notes must be strummed) to unlock the corresponding feature. To disable a cheat press Green at the 'Cheats' menu.
Air Guitar Cheat Code RY, GR, RY, RY, RB, RB, RB, RB, RB, YB, YB, YO
Hyperspeed Code - Alter the speed at which gems come down the screen. YO, YO, YO, YO, YO, RY, RY, RY, RY, RB, RB, RB, RB, RB, YB, YO, YO
Performance Mode Code - The HUD is disabled. GR, GR, RO, RB, GR, GR, RO, RB
Unlock Precision Mode - ou have to be more precise when hitting the notes. RY, RB, RB, RY, RY, YB, YB, YB, RB, RY, RB, RB, RY, RY, YB, YB, YB, RB
Large Gems Code - The gems will be bigger on the fretboard. G, R, G, Y, G, B, G, O, G, B, G, Y, G, R, G, GR, RY, GR, YB, GR, BO, GR, YB, GR, RY, GR, GY
No Fail Cheat GR, B, GR, GY, B, GY, RY, O, RY, GY, Y, GY, GR