Oh yeah, funny that you post this, considering how old this game is. it's actually one of my favorite fighters, and I thought nobody except me ever played it.
What's great about this game is its originality. Instead of having human characters, you fight with giant robots, each with its own special abilities, in a futuristic arena, plus you get to choose a pilot with different characteristics. Furthermore, the game has some sort of RPG-mode where you can upgrade your robot.
A real shame that the game was never successful and never got a sequel. It DID get a remake called One Must Fall: Battlegrounds. Like Kamui Zero said, it's a 3D fighter, which is... Different. I actually liked it but I'm probably the only one. There isn't much of a story, and the single player mode is basically a series of tournaments that are fun at first but get very repetitive and boring for a while. Apparently the makers worked hard to create original gameplay, yet as KZ said it turned just... awkward and unnatural. They should've sticked to the original formula.