here is a url for the achievments list
www.achieve360points.com/game/guitarheroiihere is some cheats and hints and such NOTE: doing cheats may make your achievments not unlockable, same thing with saints row, you do cheats you cant unlock em, but i am not sure with this game.....
mode
At the main menu, quickly press Blue, Yellow, Orange, Red, Yellow, Orange, 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 Xbox 360 to disable its effect. In the PAL version, press Blue, Yellow, Orange, Red, Yellow, Orange, Blue, Yellow, Blue, Yellow, Blue, Yellow, Blue, Yellow, Blue, Yellow at the main menu. -From: DeShaun Levy
Guitarist uses Air Guitar
At the main menu, quickly press Yellow, Blue, Yellow, Orange, Yellow, Blue. If you entered the code correctly, a message will appear. Repeat this code to disable its effect.
Guitarist has flaming head
At the main menu, quickly press Orange, Yellow(2), Orange, Yellow(2), Orange, Yellow(2), Blue, Yellow(2), Blue, Yellow(2). If you entered the code correctly, a message will appear. Repeat this code to disable its effect.
Audience has eyeball heads
At the main menu, quickly press Yellow, Orange, Blue(3), Orange, Yellow. If you entered the code correctly, a message will appear. Repeat this code to disable its effect.
Audience has monkey heads
At the main menu, quickly press Orange, Yellow, Blue(2), Yellow, Orange, Blue(2). If you entered the code correctly, a message will appear. Repeat this code to disable its effect.
Hyper Speed mode
At the main menu, quickly press Blue, Orange, Yellow, Orange, Blue, Orange, Yellow(2). 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.
Performance mode
At the main menu, quickly press Blue(2), Yellow, Blue(2), Orange, Blue(2). If you entered the code correctly, a message will appear. In this mode, everything disappears except for the performance.
Pro Face-Off mode
Successfully complete the game 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 five star rank on 20 songs.
Gibson Grabber: Successfully complete 20 songs.
Gibson Natural Maple Grabber: Get a four star rank on all songs.
Gibson Natural Sunburst Thunderbird: Get a five star rank on all songs.
Gibson Natural Thunderbird: Get a five star rank on all regular songs.
Gibson Thunderbird: Successfully complete 30 songs.
Hofner: Successfully complete all songs.
Musicman Lava Pearl Stingray: Get a five star rank on 10 songs.
Bonus guitars
Successfully complete the indicated task to unlock the corresponding guitar at the shop:
Battle Axe: Successfully complete the game on the Expert difficulty setting.
Casket: Successfully complete the game on the Medium difficulty setting.
Fish: Successfully complete the game on the Easy difficulty setting.
Eyeball: Get a five star rank on all songs on the Hard difficulty setting.
Snaketapus: Successfully complete the game 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.
Gold four stars
Hit every note in a song but strum an extra time whenever you get a 4x multiplier.