Source: Wikipedia, "Gladiator (arcade game)", available under the CC-BY-SA License.
Gladiator, known in Japan as Ougon no Shiro (黄金の城, lit. "Golden Castle"?), was a 1986 arcade game developed by Allumer and published by Taito. It was followed by a sequel titled Blandia.
The player controls a gladiator/knight named Great Guaranos as he walks through a castle. Moving the joystick left and right moves Great Guaranos left and right, and up and down is used to position Great Guaranos's shield. The game's three buttons correspond to a high, medium, and low attack with Great Guaranos's sword. Gladiator consists of 4 Stages. The first level is the 'Underground Chamber', 2nd is the 'Brick Corridor', 3rd is the 'Roof Top' stage, and the 4th stage is called the 'Mysterious 4-D World'. Your reward for completing the game is to enter the "Treasure Place".
Gameplay is split between two modes; in the "obstacle" mode, Great Guaranos walks forward, and the player must use the sword and shield to defend him from bats, fireballs, arrows, shuriken, and other flying hazards. The "obstacle" mode is broken up by a "fight" mode, in which Great Guaranos must fight against another, similarly-armored knight. In both modes, an un-defended hit to Great Guaranos knocks off part of his armor (his helmet for a high hit, his breastplate for a medium hit, and his leggings for a low hit), and a subsequent hit to the same area kills him.