I'm still waiting for that mythical Playstation 5 with the DC vs Marvel game, myself.
Yeah, I remember playing X-Men: Children of the Atom back in the day, because they had a cabinet in my high school cafeteria (back during the two or three years that they actually brought in arcade machines, before apparently realizing what a terrible idea that was and getting rid of them all).
One of the highlights of playing that was putting in the Akuma code and basically wrecking everyone else.[1] Aside from the X-Men game, the other games they had at my high school that were highlights for me were Mortal Kombat II (and then, the next year, Mortal Kombat 3), NBA Jam, and Dungeons & Dragons: Tower of Doom (and, later, Shadow over Mystara). They had some other games, too, but I don't remember what they were now.
[1] - Which, tangentially speaking, kind of reminds of when I went to a bowling alley for a birthday party for one of my nieces back in the 90s, and they had a World Heroes machine there, and I basically monopolized the player one side via Rasputin for something like 15 to 30 minutes against a group of increasingly angry teens who weren't able to beat me, until I basically just walked away to attend actual birthday party stuff.