One Must Fall: 2097 -- classic 2D PC fighter, now freeware, with a sequel on the way

http://www.omfdownloads.com/2097/omf21cd.zip

(Game is now freeware! I loved this game!)

What is OMF:BG?
Battlegrounds is the pioneer on-line, 3D, multiplayer fighting game. OMF:BG represents a serious change in the philosophy of making fighting games. Instead of 2 players facing off in a small space, Battlegrounds features up to sixteen simultaneous players in huge arenas, fighting in team battles or all-out brawls!

Our goal is to free you, the player, from the restrictions of the past, and allow you to fight the way you've always wanted to. Just like your favourite martial-arts movies, you can go toe-to-toe with several opponents, use nearby objects as weapons, and integrate terrain and hazards into your fighting strategy.

http://www.omf.com/whatis/index.html