Classic Robo War consists of six side-scrolling platformer levels freely chosen by the player. In each level, the player-character, fights through various enemies and obstacles before facing a "Robot Master" boss at the level's end. Upon defeating the boss, the player assimilates the Robot Master's signature attack, or "Special Weapon", into Robo War's arsenal for the rest of the game.
Besides the weapons taken from the Robot Masters, the player is able to pick up a platform generator item known as the "Magnet Beam" in Elec Man's stage. Robo War also features a scoring system where players score points for defeating enemies, and earn extra points for collecting power-ups from fallen enemies and for clearing each stage. When all six Robot Master stages are completed, the seventh and last stage appears in the middle of the stage select menu. This stage, in which the player traverses Dr. Wily's robot factory, is a chain of four regular stages linked together, each containing at least on
