All songs - At the main menu, select the "Extras" option. Choose the "Modify Game" selection, then press Red, Yellow, Blue, Red(2), Blue(2), Red, Yellow, Blue to unlock all songs. Alternately, press Y, B, X, Y(2), X(2), Y, B, X on a controller. Note: This code disables saving. -From: Geramie Edwards

Awesome Detection - At the main menu, select the "Extras" option. Choose the "Modify Game" selection, then press Yellow, Blue, Orange, Yellow, Blue, Orange, Yellow, Blue, Orange. Note: This code disables saving.

Stage mode - At the main menu, select the "Extras" option. Choose the "Modify Game" selection, then press Blue, Yellow, Red, Blue, Yellow, Red, Blue, Yellow, Red. Alternately, press X, B, Y, X, B, Y, X, B, Y on a controller. Note: This code disables saving.

Venue select - At the main menu, select the "Extras" option. Choose the "Modify Game" selection, then press Blue, Orange(2), Blue, Yellow, Blue, Orange(2), Blue, Yellow to unlock all venues. Note: This code disables saving.

Accomplish the indicated achievement to get the corresponding number of Gamerscore points:

Solid Gold, Baby! (25 points): Gold Star a song.
The Bachman-Turner Award (25 points): Maintain deployed Overdrive for 90 seconds.
Flawless Fretwork (25 points): Score 100% notes hit as a guitarist on Expert.
Flawless Guitar Solo (20 points): 100% a guitar solo on Expert, using only the solo buttons.
Flawless Drumming (25 points): Score 100% notes hit as a drummer on Expert.
Flawless Singing (25 points): Score a 100% rating as a vocalist on Expert.
Flawless Groove (25 points): Score 100% notes hit as bassist, up-strums only, on Expert.
Comeback Kid (15 points): Defeat the last player that defeated you over Xbox LIVE in either Score Duel or Tug of War.
Victory! (15 points): Defeat a player in either Score Duel or Tug of War.
Band Savior (20 points): Be a savior three times during a single song.
Overdrive Overdose (25 points): Achieve an 8x Band Multiplier.
Hello Cleveland! (20 points): Deploy Vocal Overdrive 4 times in a single song.
Million Point Club (25 points): Earn more than 1,000,000 points in a single song.
You're Hired! (10 points): Hire a staff member.
Needs more Umlauts! (10 points): Make a band logo.
The San Dimas 4th Annual Award (15 points): Compete in a Battle of the Bands event.
You Killed the Radio Star (15 points): Make a music video in World Tour.
Clothes to the Edge (20 points): Buy over $100,000 worth of items from the Rock Shop.
Along for the Ride (10 points): Beat an instrument-specific challenge while playing another instrument.
Challenge Novice (10 points): Complete either 25 challenges on Medium, 10 challenges on Hard, or 5 challenges on Expert.
Challenge Master (15 points): Complete 25 Challenges on Hard Difficulty or 10 Challenges on Expert Difficulty.
Challenge Savant (25 points): Complete 25 Challenges on Expert Difficulty.
The Final Countdown (15 points): Unlock an Impossible Challenge.
Groove Assassin (20 points): Beat the Impossible Bass Challenge.
Lord of the Strings (25 points): Beat the Impossible Guitar Challenge.
Stage Igniters (25 points): Beat the Impossible Band Challenge.
AN-I-MAL!!! (25 points): Beat the Impossible Drum Challenge.
Virtuoso (25 points): Beat the Impossible Vocal Challenge .
West Coast Performer (10 points): Play a set on the West Coast of North America.
Heartland Performer (10 points): Play a set in Middle America.
East Coast Performer (10 points): Play a set on the East Coast of North America.
God Save the Band (10 points): Play a set in the United Kingdom.
Western Europe Performer (10 points): Play a set in Western Europe.
Eastern European Performer (10 points): Play a set in Eastern Europe.
Worldwide Sensation (25 points): Gain access to every venue in the world.
Road Dog (30 points): Play in every venue in the world.
One Million Fans (30 points): Reach 1 million fans in World Tour.
Open Road (20 points): Win a Bus in World Tour.
Got Wheels (20 points): Win a Van in World Tour.
Jet Setter (20 points): Win a Jet in World Tour.
Beat It! (10 points): Complete all beats at 60 BPM or higher or half of the beats at 140 BPM or higher.
The Beat Goes On (20 points): Complete all beats at 100 BPM or higher or half of the beats at 180 BPM or higher.
Fill Me In (10 points): Complete all fills at 60 BPM or higher or half of the fills at 140 BPM or higher.
Fill Legend (20 points): Complete all fills at 100 BPM or higher or half of the fills at 180 BPM or higher.

Additionally, there are six secret achievements, all of which are currently unknown:

Secret achievement (35 points): Unknown.
Secret achievement (20 points): Unknown.
Secret achievement (20 points): Unknown.
Secret achievement (30 points): Unknown.
Secret achievement (50 points): Unknown.
Secret achievement (25 points): Unknown.