Fez Cheats - Xbox 360

Fly Mode
In New Game+, press [Up], [Up], [Up], [Up]+[A] while playing.

Achievements
Complete each achievement to receive the allotted gamerscore:

A numbers game (10) - Find the Counting Cube artifact.
Hexahedronaut (25) - Collect all 32 Golden Cubes and 32 Anti-Cubes.
Kill screen (25) - Get to the end.
Mightier than the sword (10) - Find the Writing Cube artifact.
Achievement unlocked (15) - RTRTLTRTRTLTLTLT.
Cryptographer (15) - Break the code.
Equal and opposite (15) - Find an Anti-Cube.
Get a cube (10) - Find your very first cube shard.
Haikus not epics (10) - Find the Tome artifact.
Sum total (40) - Find ALL collectibles.
Warp zone (15) - Reactivate all 5 warp gates.
Phrenologist (10) - Find the Skull artifact.

First Person View Sunglasses
Play New Game+ and reach the point where you recieve the Fez.

Red/Blue 3D Glasses
Collect all 64 Cubes and then go back through the Star Gate in the 32 Cube room for a different ending. After the credits, select New Game + one again from the main menu. When you reach the point in the story where you received the Fez and the Sunglasses the first two times you now get a pair of red/blue 3D glasses instead. These automatically enable Stereoscopic Mode, which can then be disabled in the Settings menu should you not want to use it.