Guitar Hero II

Cheat mode
At the main menu, quickly press Blue, Yellow, Orange, Red, Orange, Yellow, Red, Yellow, Red, Yellow, Red, Yellow, Red, Yellow, Red, Yellow to unlock all guitars, songs, videos, and cheats. Saving the game will be disabled, and you must turn off the PlayStation 2 to disable its effect. In the PAL version, press Blue, Yellow, Orange(2), Yellow, Blue, Yellow, Blue, Yellow, Blue, Yellow, Blue, Yellow, Blue, Yellow at the main menu.

Guitarist uses Air Guitar
At the main menu, quickly press Yellow(2), Blue, Orange, Yellow, Blue. If you entered the code correctly, a message will appear. Repeat this code to disable its effect. In the PAL version, quickly press Blue, Yellow, Orange, Blue, Yellow(2) at the main menu.

Guitarist has flaming head
At the main menu, quickly press Orange, Yellow, Orange(2), Yellow, Orange, Yellow(2). If you entered the code correctly, a message will appear. Repeat this code to disable its effect. In the PAL version, quickly press Yellow(2), Orange, Yellow, Orange(2), Yellow, Orange at the main menu.

Guitarist has horse head At the main menu, quickly press Blue, Orange(2), Blue, Orange(2), Blue, Orange(2), Blue. If you entered the code correctly, a message will appear. Repeat this code to disable its effect. In the PAL version, quickly press Orange(2), Blue, Orange(2), Blue, Orange(2), Blue, Orange at the main menu.

Audience has eyeball heads
At the main menu, quickly press Blue, Orange, Yellow, Orange, Yellow, Orange, Blue. If you entered the code correctly, a message will appear. Repeat this code to disable its effect. In the PAL version, quickly press Yellow, Orange, Blue, Orange, Blue, Orange, Yellow at the main menu.

Audience has monkey heads
At the main menu, quickly press Orange, Blue, Yellow(2), Orange, Blue, Yellow(2). If you entered the code correctly, a message will appear. Repeat this code to disable its effect. In the PAL version, quickly press Yellow(2), Blue, Orange, Yellow(2), Blue, Orange at the main menu.

Hyper Speed mode
At the main menu, quickly press Orange, Blue, Orange, Yellow, Orange, Blue, Orange, Yellow. If you entered the code correctly, a message will appear. In this mode, the frets will move faster. Repeat this code to disable its effect. In the PAL version, quickly press Yellow, Orange, Blue, Orange, Yellow, Orange, Blue, Orange at the main menu.

Performance mode
At the main menu, quickly press Yellow(2), Blue, Yellow(2), Orange, Yellow(2). If you entered the code correctly, a message will appear. In this mode, everything disappears except for the performance. Repeat this code to disable its effect. In the PAL version, quickly press Yellow(2), Orange, Yellow(2), Blue, Yellow(2) at the main menu.

Pro Face-Off mode
Successfully complete Career mode on the Medium difficulty setting to unlock Pro Face-Off mode. This mode allows two players to play all the notes.

Bonus basses
Successfully complete the indicated task in Co-op mode to unlock the corresponding bass at the shop for Co-op mode:

Gibson Cherry SG: Successfully complete 10 songs.
Gibson Cream SG: Get a golden five star rank on all 40 original songs.
Gibson Grabber: Successfully complete 20 songs.
Gibson Natural Maple Grabber: Get a golden five star rank on every song.
Gibson Natural Thunderbird: Get a five star rank on all of the regular songs.
Gibson Thunderbird: Successfully complete 30 songs.
Hofner Sunburst Classic : Get a five star rank on every song including the bonus songs.
Musicman Lava Pearl Stingray: Successfully complete 21 songs with a five star rank.

Bonus guitars
Successfully complete the indicated task to unlock the corresponding guitar at the shop:

Battle Axe: Successfully complete Career mode on the Expert difficulty setting.
Casket: Successfully complete Career mode on the Medium difficulty setting.
Eyeball: Get a five star rank on all songs on the Hard difficulty setting.
Fish: Successfully complete Career mode on the Easy difficulty setting.
Snaketapus: Successfully complete Career mode on the Hard difficulty setting.
The Log: Get a five star rank on all songs on the Expert difficulty setting.
U.S.A.: Get a five star rank on all songs on the Easy difficulty setting.
Viking: Get a five star rank on all songs on the Medium difficulty setting.

Bonus songs
Successfully complete the indicated task on the Medium or higher difficulty setting to unlock the corresponding song:

Tonight, I'm Gonna Rock You Tonight: Successfully complete the first set and do the encore.
Carry On My Wayward Son: Successfully complete the second set and do the encore.
War Pigs: Successfully complete the third set and do the encore.
Sweet Child O' Mine: Successfully complete the fourth set and do the encore.
Last Child: Successfully complete the fifth set and do the encore.
Stop: Successfully complete the sixth set and do the encore.
YYZ: Successfully complete the seventh set and do the encore.
Free Bird: Successfully complete the eighth set and do the encore.

Full Rock meter
Start a song and max out the Rock meter, then reset the song to start with a full rock meter.

Gold four stars
Hit every note in a song but strum an extra time whenever you get a 4x multiplier.

Use Scythe guitar with any character
Unlock the Grim Reaper. Go to Career mode and choose him. Then, go to change your character and select anyone. It should say they are using the Scythe. Play a live show and they will be using it.

Unlock the Grim Ripper. Go to Career mode and choose him. Then, select another character whose alternate costume is already unlocked, and they will have the Scythe unless you change the guitar. Note: Since Clive Winston and Xavier Stone do not have an unlockable costume, they cannot play the Scythe.

Getting the Grim Ripper to play something other than the Scythe
The following trick requires the Grim Ripper and two files (medium and hard). In your second file, set the Grim Ripper as your character. Then, go into your first file and play as someone else. Give him or her a new guitar. Go back to your second file. The Grim Ripper should now have another guitar other than the Scythe.

Unlock the Grim Ripper, select him in Career mode, then exit Career mode. Go to Quick Play mode, choose any song on any difficulty, and either finish the song or quit once it has started. Then, go back to Career mode, and the Grim Ripper will be playing the Gibson Les Paul with the Cherry Sunburst Classic skin. To make him play the Scythe again, simply select it in the "Change Guitar" menu.

Use the following trick to get the Grim Ripper to play a guitar from the original Guitar Hero. You must have the Grim Ripper, and two files (medium and hard) to do this trick. In your second file, set the Grim Ripper as your character. Then, go into your first file and play as someone else. Give him or her one of the unlockable guitars. Go back to your second file. The Grim Ripper should have a Gibson Les Paul Cherry Sunburst Classic (which is not available for purchase in Guitar Hero 2.