Robo Army (set 2) is likely a second set or version of the Robo Army arcade game. This variation could involve updated graphics, levels, gameplay mechanics, or other differences compared to the original Robo Army.  It may have been produced by the same developer or a different one depending on the nature of the differences between the sets.  More information is needed to identify the specific developer and publisher of this variation.

Robo Army (set 2)

Road Fighter (set 3, conversion hack on Hyper Sports PCB)