To enter cheats, from the main menu go to Options -> Cheats -> Enter New Cheat. For each code, you have to strum while you press the given buttons. Notes in parenthesis are held together while you strum.
Also, there are five levels of hyperspeed in GH3. Level 5 is INSANITY to say the least. To switch between them, you press the green button while the code is highlighted after you enter it.
All codes except Unlock All Songs may be turned off directly from the cheat menu by pressing the green button.
| Cheat | Effect |
|---|---|
| OBOYOBOY | Hyperspeed |
| (GR) (GR) (GR) (RY) (RY) (RB) (RB) (YB) (YO) (YO) (GR) (GR) (GR) (RY) (RY) (RB) (RB) (YB) (YO) (YO) | Precision Mode |
| (RY) (RB) (RO) (RB) (RY) (GB) (RY) (RB) | Performance Mode |
| (YO) (RB) (RO) (GB) (RY) (YO) (RY) (RB) (GY) (GY) (YB) (YB) (YO) (YO) (YB)YR(RY)RYO | Unlock All Songs |
| (YB) (GY) (GY) (RB) (RB) (RY) (RY) (YB) (GY) (GY) (RB) (RB) (RY) (RY) (GY) (GY) (RY) (RY) | Air Guitar |
| (GR) B (GR) (GY) B (GY) (RY) O (RY) (GY) Y (GY) (GR) | No Fail (does not work in career mode) |
| 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 | Large Gems |
| (GR_BO) (GRYB_) (GRY_O) (G_BYO) (GRYB_) (_RYBO) (GRYB_) (G_YBO) (GRYB_) (GRY_O) (GRY_O) (GRYB_) (GRY_O) | Unlock Everything (uses 4-note chords, no sound will play) |
| (GR) (GY) (YB) (RB) (BO) (YO) (RY) (RB) | Easy Expert (makes the timing window bigger for hitting notes, Cannot be used in single career mode.) |
