Fighting games usually rehash the same old styles (Karate, Kung Fu, Taekwondo etc) but I think it would be interesting to see a videogame that uses none of those styles but more obscure or less popular ones. Here is my idea for some styles that would be cool to see in a new fighting game that would introduce players to styles unfamiliar to them.

Wing Chun... Jet Li’s signature style used in many of his films
Muay Boran... the predecessor to Muay Thai and much more brutal
Krav Maga... self-defense system used by Israeli commandoes and Mossad agents
Pencak Silat... Indonesian martial arts seen in the film The Raid: Redemption
Eskrima... Filipino martial arts with a focus on two-handed knife and stick fighting
Lucha Libre... Mexican version of pro-wrestling
Savate... French kickboxing used by the villains in the Jet Li film Kiss of the Dragon
Taijutsu... the hand-to-hand aspect of traditional Ninjutsu
Bak Mei... a brutal Kung Fu style used by Pai Mei in the film ‘Kill Bill Part 2’
Keysi Fighting Method... also known as the ‘Batman fighting style’
Kapu Kuialua... Hawaiian ‘bone-breaking’ martial arts
Kalaripayattu... ancient Indian style with animal styles i.e. horse, elephant etc.

And here are a few fictional martial arts
Baritsu... the “scientific boxing” and staff-style used by Sherlocke Holmes
Meyraiyuth... ‘drunken-Muay Thai-break-break dancing’ seen in the Thai film ‘Raging Phoenix’
Gun-Kata... the ‘gun fighting style’ seen in the film Equilibrium


My other idea would be a game with an emphasis on Kung Fu (one that features hard and soft styles).

This game would be similar to Tao Feng: Fist of the Lotus with two opposing factions that use their own style of Kung Fu. The gameplay would be more open-world with action scenes inspired by Wuxia films to encourage players to use the environment and traditional Kung Fu weapons that would be scattered throughout the stages.

“Good guy” styles
Tai Chi
Shaolin Fist
Baguazhang
Wing Chun
White Crane
Hung Gar
Monkey
Jeet Kune Do (a "modern" kung fu style)

“Bad guy” styles
Dim Mak (literally ‘Touch of Death’)
Snake Style
Xing Yi
Tiger Claw
Bak Mei (Pei Mei's style in Kill Bill 2)
Praying Mantis
Sanshou (more like kickboxing)
Drunken Fist

Kung Fu Weapons

Gun (wooden staff)
Jian (straight sword)
Dao (broadsword)
Qiang (spear)
Guandao (pole weapon with a curved blade)
Monk’s Spade (a staff with a spade-shaped blade)
Butterfly Knives
Rope Knife
Three-Sectional-Staff
Nunchaku