Capcom weren't having a very good 1994, at least fighting game wise. Super Street Fighter II Turbo had underperformed in arcades, and Darkstalkers didn't see much success outside of Japan. However, one of their last games of the year turned out to be the hit they were after: X-Men Children of the Atom. Whilst Capcom's first Marvel game, The Punisher, had been a scrolling beat 'em up, Children of the Atom was a one on one fighting game, a genre which was extremely popular.
The game featured the best 2D graphics ever seen, with incredibly detailed sprites and featured stages that had changing backgrounds -you could smash through the floor on Colossus' stage for example, and Omega Red's stage would go deeper and deeper into the sea. Gameplay was like a more extreme version of Street Fighter II -characters can pull off massive combos, and movement is much faster due to the dashes and super jumps.
The success of Children of the Atom led to it being ported to the SEGA Saturn, PC and eventually Playstation. Thanks to this, Capcom would go on to make several more great Marvel titles, most of which were all fighting games.