X-Men: The Official Game Codes -

Iceman Danger Room missions
At the Cerebro Files menu, press x2, x2, , , , , to unlock the bonus Iceman Danger Room missions.

Nightcrawler Danger Room missions
At the Cerebro Files menu, press x2, x2, , , , , to unlock the bonus Nightcrawler Danger Room missions.

Achievements
Complete each achievement to get the allotted gamerscore:

Champion Iceman (70) - Collect all Sentinel Tech as Iceman.
Champion Nightcrawler (70) - Collect all Sentinel Tech as Nightcrawler.
Champion Wolverine (110) - Collect all Sentinel Tech as Wolverine.
Danger Room Iceman (20) - Complete Act 1 of the game.
Danger Room Nightcrawler (20) - Complete Act 2 of the game.
Danger Room Wolverine (30) - Complete Act 3 of the game.
Evolution Iceman (125) - Iceman has been upgraded with all available mutations.
Evolution Nightcrawler (125) - Nightcrawler has been upgraded with all available mutations.
Evolution Wolverine (120) - Wolverine has been upgraded with all available mutations.
Secret Identity Iceman (70) - Collect all Weapon X Files as Iceman.
Secret Identity Nightcrawler (80) - Collect all Weapon X Files as Nightcrawler.
Secret Identity Wolverine (110) - Collect all Weapon X Files as Wolverine.
X-Men (50) - Accumulate 950 achievement score.
Xavier Institute Iceman (0) - Complete Iceman's training mission.
Xavier Institute Nightcrawler (0) - Complete Nightcrawler's training mission.
Xavier Institute Wolverine (0) - Complete Wolverine's training mission.

Bonus costumes
Collect all Weapon X files with a character to unlock their street costume. Collect all Sentinal Techs with a character to unlock their comic costume.