EuroGamer Challenge Room:
Press Down, Up, Down, Up, Left, LB, X, LB, X, Y, Start at the "Press Start" screen to unlock the EuroGamer challenge room at the "Challenge Room" menu.
GamesRadar Challenge Room:
Press RB, Y, X, X, Up, Down, LB, LB, Up, Down, Start at the "Press Start" screen to unlock the GamesRadar challenge room at the "Challenge Room" menu.
IGN Challenge Room:
Press Up, Down, Y, X, X, Y, Down, Up, LB, LB, Start at the "Press Start" screen to unlock the IGN challenge room at the "Challenge Room" menu.
Achievements:
Meet with annihilation
Reward: 20 Points
Objective: Kill all foot soldiers and enemy trucks on a Meet With Enemy sequence.
The Emperor's New Clothes
Reward: 20 Points
Objective: Obtain the Shin Guards, the Bulletproof Vest and the Helmet.
Private Arsenal
Reward: 20 Points
Objective: Obtain every weapon and weapon upgrade.
Faster Than a Speeding Bullet
Reward: 20 Points
Objective: Block 100 projectiles using the claw.
One Dozen Yashichis
Reward: 20 Points
Objective: Collect all twelve hidden Yashichis - one from each of Area 01 - 12.
Clean as a whistle
Reward: 20 Points
Objective: Clear Area 02 without touching a slime blob.
Pacifist Pride
Reward: 20 Points
Objective: Clear any of Area 1 - 12 without firing your gun.
Cat burglar
Reward: 20 Points
Objective: Get to the boss of Area 05 within one minute and thirty seconds.
A Real Challenge
Reward: 20 Points
Objective: Acquire at least one star in each of the Challenge Rooms 1 - 56.
H4><0rz
Reward: 10 Points
Objective: Hack through all the hacking games on Hard.
Intel Collector
Reward: 5 Points
Objective: Acquire all database logs.
Elite Commando
Reward: 5 Points
Objective: Clear the game on Super Hard.