• Cyclops

Choose Cyclops when selecting a character. He has no punch combo, so you can continuously punch one enemy till he is KOd without having to stop, unlike the other X-men who can only punch three or four times. Note: This will not work on most Bosses. mini-Bosses and Sentinels.
  • Defeating Night Crawler

Knock Night Crawler onto the spikes that appear from the floor. Keep punching him, and the spikes will help kill him quickly, often without hitting you back.
  • Play As Bosses

Complete the single-player mode. When you hook up the Game Boy Advances and select a mode, you can choose from Bosses (but not mini-Bosses).
  • Special move

Press A + B to do a special move. Note: This takes away a little bit of life.