FightingGameGuy on 10 December 2007
Powerstone I or II for the Dreamcast. Two is a bit more party oriented. In fact, I don't even remember if one has four players simultaneous.
There's also a lot of games with tag or "team" modes where you swap which player and/or character is in but don't have true multiplayer simultaneous combat.
Also, though the Worms series aren't actually fighting games (though they have 2-D gameplay and hp =D), they rock for competitive, fun, multiplayer. Instead they are a turn-based yet realtime, 2-D, wtf is going on, strategy game.
