SNK made many great games for the Neo Geo, and in many genres such as beat em ups. One of their best beat em ups was the Sengoku series, a series about brawlers taking on specters of the warriors of japans past along with ghosts and demons. In the first game, you could get various weapons and summon others to swap places with, for extra abilities. The series only got better and better, and to be honest, this is one that SNK should really consider bringing back.
Brawlers are making a comeback now, both in 2D and 3D styles and with the various innovations Sengoku and its sequels introduced, this could be a truly innovative open world brawler. You would travel between worlds/dimensions and fight enemies as you go, but you could also do things like in the original games, like shatter enemies weapons to force them to fight you hand to hand, and swap places with others you meet on the way. The enemy variety and different locales would all contribute well to this, and this could be one of the most unique brawlers ever made.
SNK is slowly getting back into game making after their pachinko era, and games like King of Fighters XIV show they have what it takes to still make great games. SNK could very well make a great open ended brawler for modern systems and PC, or if they want, make a throwback retro style 2D beat em up. They could even work with a company like WayForward to do for Sengoku what was done for Double Dragon with Double Dragon Neon.
The simple matter is, that the Sengoku series offered a great twist on the beat em up genre and this is greatly missed today. A proper return would be welcome and a sign that SNK has more than just fighting games up their sleeves.