Super Meat Boy Cheats - Xbox 360

Unlock Brownie
Enter [R]+[B], [R]+[B], [R]+[B], [B], [B], [B], [X] at the character selection screen before starting a level, then select a character (most characters will work, but not certain ones like Gish and Alien Hominid). You must beat the boss at the end of the Salt Factory first.

Achievements
Complete each achievement to receive the allotted gamerscore:

Business Time (10) - Collect 50 bandages.
I'm A Golden God! (20) - 100% the game
Nostalgia (15) - Find and unlock a warp zone.
Sticky fingers (5) - Collect 10 bandages.
The Commander (10) - Find and unlock Commander Video.
Iron Boy! (10) - Complete a full chapter without dying.
Living in the Past (20) - Find and complete 5 warp zones.
The End (65) - Complete the main game.
The Real End (20) - Complete the Dark World.
Tin Boy (5) - Complete 10 levels consecutively without dying.

Additionally, there are two secret achievements:

Suffragette (10) - You've beaten the Cotten Alley all by yourself!
The Kid (10) - You unlocked The Kid.

Unlock Avatar Awards
Super Meat Boy - Beat the Light World.
Super Meat Boy T-Shirt - Play the game for a few minutes.

Unlock Brownie Gamerpic
Beat Brownie in a Race.

Unlock Characters
4 Color Meat Boy - Collect 80 bandages.
4Bit Meat Boy - Collect 60 bandages.
8Bit Meat Boy - Collect 40 bandages.
Alien Hominid - Collect 30 bandages (Xbox 360 version only).
Captain Viridian - Collect 90 bandages (PC version only).
Commander Video (Bit Trip) - Complete the Warp Zone in World 1.
Flywrench - Complete The Fly Guy! Warp Zone in World 4-18.
Gish - Collect 10 bandages (Xbox 360 version only).
Goo - Collect 10 bandages (PC version only).
Jill (Mighty Jill Off) - Complete the Warp Zone in World 2.
Josef - Collect 30 bandages (PC version only).
Meat Ninja - Have 100% game completion. Note: Leaderboards will be disabled while playing as this character.
Mr. Minecraft - Collect 100 bandages (PC version only).
Naija - Collect 50 bandages (PC version only).
Ninja (N+) - Collect 100 bandages (Xbox 360 version only).
Ogmo (Jumper) - Complete The Jump Man! Warp Zone in World 3-16.
Pink Knight (Castle Crashers) - Collect 90 bandages (Xbox 360 version only).
Runman - Collect 70 bandages (PC version only).
Spelunky - Collect 70 bandages (Xbox 360 version only).
The Headcrab - Collect 10 bandages (PC version only).
The Kid (I Wanna Be the Guy) - Complete The Guy! Warp Zone in World 5-7.
Tim (Braid) - Collect 50 bandages (Xbox 360 version only).

Unlock Teh Internets Chapter
Collect 20 bandages.

Unlock the Glitch Levels
Reach Bandage Girl when her model is glitched in any level after defeating the Chapter Boss.