Iceman Danger Room missions
     At  the  Cerebro  Files  menu, press Right(2), Left(2), Down, Up,
Down, Up, Enter to unlock the bonus Iceman Danger Room missions.

Nightcrawler Danger Room missions
     At  the  Cerebro  Files  menu, press Up(2), Down(2), Left, Right,
Left,  Right,  Enter  to  unlock  the  bonus  Nightcrawler Danger Room
missions.

Wolverine Danger Room missions
     At  the  Cerebro  Files  menu, press Down(2), Up(2), Right, Left,
Right, Left, Enter to unlock the bonus Wolverine Danger Room missions.

Danger Room missions
     Successfully  complete  an  Act with a character to unlock one of
their Danger Room mission. Successfully complete all three Acts with a
character to unlock all three of their bonus Danger Room missions.

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.

Finding Tech Pieces
     To  save time and frustration looking for Tech Pieces, go through
the  level  on  novice  to  find  all six Tech Pieces, then distribute
mutation  and  save  the game. Go back on the higher levels to get the
missing mutations, without worrying about racing around trying to find
the pieces (especially on timed missions).