Heroes

• Beast - Possesses ape-like superhuman physical strength and agility
• Cyclops- Produces powerful optic blasts from his eyes, forcing him to wear specialized visor at all times.
• Gambit - Has the ability to manipulate kinetic energy and is also skilled in card-throwing, hand-to-hand combat, and the use of a staff.
• Psylocke- The only X-Man woman in the game, she can use her telepathic powers to form a 'psychic blade' with her fists. She has the most techniques of all the playable characters.
• Wolverine - A gruff mutant possessing animal-keen senses, enhanced physical capabilities and adamantium claws. (However, unlike some other X-Men games, Wolverine cannot heal himself automatically)

Villains

• Acolytes - Only appearing in the final level of the game, they can teleport around the room and fire homing energy at the player.
• Apocalypse - The supposed mastermind behind the events at Genosha.
• Brood - A race of insect-like, parasitic, extraterrestrial beings that possess wings, fanged teeth and a stinging tail. They have a hive mentality and mindlessly follow their queen.
• Brood Queen - The leader of the Brood and one of the bosses that the X-Men must face.
• Exodus - Magneto's guardian aboard the "Avalon." Exodus can teleport around the room and fire laser beams from his eyes. Exodus can also summon Acolytes to aid him in battle. When half of his health is gone, Exodus will retreat from the battle.
• Genoshan Magistrates - The common fodder enemies. Some are armed with weapons such as grenades, knives and guns.
• Juggernaut - Like Omega Red, he appears as a test simulation in the Danger Room once he is defeated.
• Magneto - The true mastermind behind all the events leading up to this point. Magneto resides in his personal space colony "Avalon" and uses the powers of magnetism to generate an electrical shield, attract and fire metal scraps, and fire paralyzing electromagnetic energy.
• Omega Red - He appears as a test simulation to test the X-Men's skills in the Danger Room.
• Sentinels - The other fodder-class enemies that the player must face. There are three boss battles involving the Sentinels: Wolverine fights a giant unfinished Sentinel that is still in the works, Psylocke fights a Sentinel on an elevator at the end of her stage, and Beast combats against three Sentinels in hand-to-hand combat.
• Tusk - A powerful mutant who has superhuman strength and the ability to create smaller duplicates of himself that do his bidding, named "Tuskettes".
• Tuskettes - The minions of Tusk. They attack by grabbing onto their victims to hold them in place while throwing bombs at them.