* FakeBrit - Canadian Creator/JenniferHale as the Scarlet Witch (who isn't British). Then again, Scarlet Witch was born and raised in a fake country. Who's to say what her accent sounds like? In a straighter example, Armin Shimerman (American) as the English mutant Toad.
* FakeNationality - Many of the foreign X-Men, ranging from JustAStupidAccent (Colossus, Nightcrawler), to NotEvenBotheringWithTheAccent (Magneto, who like in other adaptations doesn't even remotely sound Polish).
* CowboyBebopAtHisComputer: One of the trivia questions in the second game is to name which alien race the X-Men have never encountered. The in-game answer? Skrulls. This is in spite of the fact that at the time the game came out, there had already been ''two'' arcs where the X-Men had encountered the shape-shifting race[[note]]The first running through ''Uncanny X-Men'' #275-277 and the second going through ''Uncanny X-Men'' #368-370 and ''X-Men'' #88-90[[/note]].
* TheOtherDarrin: Several voice actors were changed from the first game to the second, but most of the changes were minor.
** Magneto, sadly, lost the magnificent baritone of Creator/TonyJay. Richard Green ([[WesternAnimation/TheBatman Hugo Strange]], [[WesternAnimation/TransformersPrime Skyquake]]) voiced him in the second game.
** Earl Boen ([[Franchise/{{Terminator}} Dr. Silberman]], [[VideoGame/MonkeyIsland the ghost pirate LeChuck]]) is Colossus in the first game. Creator/JimWard is Colossus in the second game, as well as [[ComicBook/AlphaFlight Guardian]].
* RoleReprisal:
** Creator/PatrickStewart reprises his role from the [[Film/{{X-Men}} movies]] as Professor Xavier.
** Likewise, RobinAtkinDownes reprises his role from ''VideoGame/XMenNextDimension'' as Pyro and takes on the role of Cyclops in the first game (while absent in the second game, he'd later reprise the role of Cyclops in the first ''VideoGame/MarvelUltimateAlliance'' game).
** This series would also be the first time Creator/SteveBlum and Peter Lurie voiced their respective roles of ComicBook/{{Wolverine}} and ComicBook/{{Sabretooth}}, with both reprising their roles in ''MarvelUltimateAlliance'', ''WesternAnimation/WolverineAndTheXMen'' and ''WesternAnimation/UltimateSpiderMan'' and Steve as Wolverine [[WesternAnimation/TheAvengersEarthsMightiestHeroes a]] [[WesternAnimation/HulkVS lot]] [[VideoGame/SpiderManWebOfShadows of]] [[WesternAnimation/TheSuperHeroSquadShow times]] [[VideoGame/MarvelVsCapcom3 since]].
* WhatCouldHaveBeen: DummiedOut content in the PC version of the second game indicated that Dazzler was planned as a playable character at some point.