Activate the following cheats by pressing the corresponding sequences of buttons during game play:
Classic Wolverine Yellow/Blue Costume - X, square, circle, square, X, triangle, X, triangle, X, square, circle(2), square, R3.
Faster Enemy Reflex - X(2), square(2), triangle(2), circle(2), triangle(2), square(2), X(2), R3.
Invincibility - X(2), square(2), triangle(2), circle(2), triangle(2), X(2), R3.
Infinite Rage - triangle, square(2), triangle, circle(2), X(2), triangle, R3.
Immortality - square, X(2), square, triangle(2), square, circle(2), square, R3.
To unlock a secret costume, first beat the game. This will unlock another Challenge in the bonus room. Beat the Challenge to unlock a the secret costume.
Unlock the following costumes by performing the corresponding Challenges:
Blue/Yellow Wolverine costume - Collect the two action figures of classic wolverine. Then, complete classic wolverine challenge.
Brown/Yellow Wolverine costume - Collect the two action figures of legendary wolverine. Then, complete legendary wolverine challenge.
X-Force costume - Collect the two action figures of x-force wolverine. Then, complete x-force wolverine challenge.
To unlock Hard difficulty, beat the game.
To unlock 3D mode, beat the game on Hard difficulty.
Mysterious hatch location:
On the first level at the Gatecrasher objective, crash the jeep through the gates killing all enemies. To the left of the gate there is a boarded up door. Cut the boards down, and enter it to find the mysterious hatch.
References easter eggs:
Portal reference - The Cake is a reference to Portal "The Cake is a lie"
Lost reference - The mysterious hatch is a reference to the hatch on lost at the end of the first series.
World Of Warcraft reference - The WoW! trophy is a reference to World Of Warcraft
A Day's Work - Kill 500 enemies.
Aerial Assault - Perform 10 air grabs.
Aerial Master - Get 6 enemies airborne at the same time.
Apprentice - Raise a combat reflex to master level.
Astonishing - Found 1/2 of all dog tags in the game.
Bloodlust - Killed 50 enemies while in berserker mode.
Boomerang - Killed 25 enemies with a reflected projectile.
Catch! - Killed 1 enemy with a reflected projectile.
Clean Up on all Aisles - Destroyed all objects in the grocery store fight with fred dukes (the blob).
Defensive - Perform 1 counter move.
Drop Dead - Kill 10 enemies by throwing them off high areas.
Efficient Killer - Quick kill 20 enemies.
Environmentally Friendly - Killed 10 enemies using objects in the environment.
Found! - You found a mysterious hatch!
Fully Loaded - Max out all upgrades.
Getting Started - Kill 100 enemies.
Heightened Senses - Kill 200 enemies in feral sense.
Hot Potato - Light 20 enemies on fire.
James Howlett - Perform a wolverine to wolverine lunge.
Lunge - Lunge at 25 enemies.
Mutant Lover - Raise a mutagen to level 3.
Perfect Killer - Quick kill 3 enemies in a row.
Piggy Back Ride - Lunge at a W.E.N.D.I.G.O prototype's back.
Pounce - Lunge at 100 enemies.
Quick Killer - Quick kill an enemy.
Shotgun Epic Fail - Kill 25 ghosts with their own weapon.
Slaughter House - Dismember 100 enemies.
Slice n' Dice - Kill 6 enemies with one attack.
Spillway Escape - Escape from weapon x.
Stick Around - Impale victor creed outside the bar.
The Cake - You found the cake, yummy!
Threading the Needle - Flew through the o ring in the sentinel boss battle.
Ultimate Wolverine - Fought 4 W.E.N.D.I.G.O prototypes at the same time and defeat them at alkali lake.
Untouchable - Perform 25 counter moves.
Weapon X - Killed 150 enemies while in berserker mode.
Whatever it Takes - Killed 30 enemies using objects in the environment.
WoW! - You feel a cold as you examine the sword and skeleton. A rustle of wind in the trees faintly echoes the name arthas.
You Can't Hide - Lunge at 250 enemies.
52 Pickup - Defeat remy lebeau (gambit).
Bar Fight - Defeat victor creed (sabretooth).
Blender - Kill 200 enemies with claw spin.
Devil's Brigade - Found all dog tags in the game.
Fallen Sentinel - Defeat the sentinel mark I.
Helicopter Ride - Defeat david nord (agent zero).
Put up your Dukes - Defeat fred dukes (the blob).
Samurai - Raised all combat reflexes to master level.
The Village - Completed the jungle mission.
What I Do Best - Kill 2000 enemies.
The Dead Pool - Defeat weapon 11 (deadpool).
Walking Death - Beat the game on hard difficulty.
Platinum - Collect all other trophies.