9.5 Fighting games
For most they are usually broken into fixed stage (street fighter, tekken, powerstone) and scrolling stage (Streets of Rage, Golden Axe, earlier Castlevania games) but that is not that useful as many times the scrolling stage will be an illusion as you might walk on and then get a signal to continue after defeating so many enemies. The distinction between 2d and various forms of 3d are also possible.