Mega Man consists of six side-scrolling platformer levels freely chosen by the player. In each level, the player-character, Mega Man, 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 Mega Man’s arsenal for the rest of the game.
Unlike the standard Mega Buster, the Robot Master powers have limited ammunition replenished by collecting ammunition cells dropped by defeated enemies at random.Enemies also drop energy cells that replenish Mega Man’s health gauge.While the player is free to proceed through the game in any order, each Robot Master is especially vulnerable to a specific weapon, which encourages the player to complete certain stages before others. The player can also revisit cleared levels. 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.
Mega Man 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. Each Robot Master was worth a random number between 50,000 and 100,000 points whereas Dr. Wily was always worth 200,000 points. The scoring system was removed in later Mega Man games as it was found to provide no meaningful benefit to players and felt unnecessary to designers.
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 one new boss. During these final stages, the six Robot Masters must also be fought again in a predetermined order before the final confrontation against Dr. Wily. As Mega Man’s health and ammo are not restored between stages, every action the player takes is consequential