Achievements...
	Arron Sedillo challenge room...
	Fake Pause / Invincibility...
	GamesRadar challenge room...
	Major Nelson challenge room...
	Retro costume...
	Secret Challenge Rooms...
	Unlock Super Hard Difficulty...

Complete the following achievements to unlock Xbox Live Gamerscore points.

Achievement	How to unlock
A Real Challenge ( 20 points )	Acquire at least one star in each of the Challenge Rooms 1 to 56.
Cat burglar ( 20 points )	Get to the boss of Area 05 within one minute and thirty seconds.
Clean as a whistle ( 20 points )	Clear Area 02 without touching a slime blob.
Elite Commando ( 5 points )	Clear the game on Super Hard.
Faster Than a Speeding Bullet ( 20 points )	Block 100 projectiles using the claw.
Frank is that YOU? ( 11 points )	Defeat a Franken without taking any damage.
H4><0rz ( 10 points )	Hack through all the hacking games on Hard.
Hey Doc! It's GO time! ( 42 points )	Defeat the final boss.
Intel Collector ( 5 points )	Acquire all database logs.
Master Wrangler ( 13 points )	Score the most ZGU's in an online Skirmish match.
Meet with annihilation ( 20 points )	Kill all foot soldiers and enemy trucks on a Meet With Enemy sequence.
New Ooze ( 10 points )	Destroy every Gloomex canister.
One Dozen Yashichis ( 20 points )	Collect all twelve hidden Yashichis - one from each of Area 01 to 12.
Pacifist Pride ( 20 points )	Clear any of Area 1 - 12 without firing your gun.
Private Arsenal ( 20 points )	Obtain every weapon and weapon upgrade.
Staff Infection ( 10 points )	Capture or Destroy all 10 Frozen Codebase shirt wearing zombies.
The Emperor's New Clothes ( 20 points )	Obtain the Shin Guards, the Bulletproof Vest and the Helmet.
Undead Basket ( 10 points )	Complete a survival mission only using your wrangler pack.
You're Not Brain Dead ( 4 points )	Wrangle a Zombie.
Valley of Fortune ( 20 points )	Find 20 Zombie Tarot Cards.
Voodoo Magic ( 14 points )	Find 20 Voodoo Dolls.
Zombie Assassin! ( 13 points )	Kill 25 Zombies using your ranged weapon in online Ranked Skirmish.
Zombie Horde ( 20 points )	Suck up 50 zombies in campaign, co-op, Ranked Multiplayer.
Zombification ( 33 points )	Play online with a player who carries the infection.

Press Right, Down, Left, Up, LB, RB, Y(2), A(2), Start at the "Press Start" screen to unlock a fan made challenge room at the "Challenge Room" menu.

At any point in the game, press the Guide button and immediately press Back. You must press guide a fraction of a second BEFORE you press back. The guide will come up like normal so leave the guide and go back to the game. You'll notice that the game is paused yet everything is still moving! Enemies will still fire at you and everything will move except you. You can't move of course but an interesting property is that you cannot take damage or be affected by ANYTHING. That's right! You are invincible while it's paused! Use this trick on the Fabricator for an easy win! You can also start a swing and do the glitch to fly through electrical gates or other obstacles without taking damage!

Press RB, Y, X(2), Up, Down, LB(2), Up, Down, Start at the "Press Start" screen to unlock the GamesRadar challenge room at the "Challenge Room" menu.

Press LB, X(3), Right, Down, LB, Left, Y, Down, Start at the "Press Start" screen to unlock the Major Nelson challenge room at the "Challenge Room" menu.

Press Up, Left, A, Y, Up, Down, Left, Right, X, B, A, Down, B, Y, Start during game play.

At the menu screen where it says "Press Start," enter these codes, quickly.

Code	Effect
Up, Down, Y, X, X, Y, Down, Up, LB, LB, Start	Unlocks IGN Challenge Room for Xbox 360 (also works on PC version with 360 controller input)
Down, Up, Down, Up, Left, LB, X, LB, X, Y, Start	Unlocks Eurogamer Challenge Room for Xbox 360 (also works on PC version with 360 controller input)

Beat the game on any difficulty.