Lethal League Blaze is the most interesting fighting game that I haven't played.

 

Lethal League Blaze is an indie fighting game created by TeamReptile, where the main draw of the game is the unique form of "combat" within the fighting game genre. When a match starts, an anti gravity baseball is placed in the center of the arena. This is the only way to deal damage to a player. The bulk of the combat is trying to hit it and create a chain of hits to increase the momentum of the ball, causing it to fly around the screen extremely fast. The player, however, can cancel all momentum from the ball by bunting it. I can't explain the gameplay very well because it requires a bachelor's degree in trigonometry, which I do not in fact have, but check out YakkoCMN's video about the game to learn more about it (mild language if that's an issue).