Doug Buel writes: "The game's story mode explains the plot. Superman blasts Darkseid through a dimensional gate at the same time that Raiden does the same to Shao Khan. The coincidence fuses the two dimensions, which basically means everybody has to fight everybody. After all, it's a fighting game.
There's an almost epic story mode in this game, with two versions. You can pick the DC-oriented tale or the "Mortal Kombat" one. Most story modes in fighting games are terrible, but this one is pretty good. In contrast is Arcade mode, which has dull voiceover endings."