If you are using nightcrawler,teleport him if the bad guys wanted to shot you.You can press O to teleport behind the enemies.
When you go against the fire serpent don't mind the Raptors that flies direct your target there use Icebeam to finish it off. Don't do anything but hit the Fire Serpent with your Icebeam after a few moments the Fire serpent dies.
Enter the following codes on the Cerebro Files Menu Screen. Press start after each code to activate
Unlocks Wolverine's Danger Room
Down, Down, Up, Up, Right, Left, Right, Left
Unlock Nightcrawler's Danger Room
Up, Up, Down, Down, Left, Right, Left, Right
Unlock Iceman's Danger Room
Right, Right, Left, Left, Down, Up, Down, Up
When you are playing iceman very first mission,you can freeze the fountain by preesing the O.