Spinal Breakers (US, prototype)

Spinal Breakers is a 1990 shooting action arcade game developed by Video System and published by American Sammy. Set in the future, a nuclear war has resulted in the futuristic Hildroids - robots created to serve humans - to develop their own intelligence and turn against their creators. Hijacking a time machine made by humans, entire groups of Hildroids have escaped into the past, masquerading as humans into infiltrating human society in different time periods, with the intentions of rewriting history and wipe out the ancestors of mankind.

Captain Waffle, a soldier from the past waking up from cryogenic sleep, learns of the truth. Boarding a Time Machine, it's up to the Captain to fight rogue Hildroids through time, before returning to the Hildroids' lab in America for a final battle.