Mega Man 4 features similar gameplay to the previous three games.
The player must complete a series of eight stages in an order of the player’s choosing. The protagonist, Mega Man, is able to run, jump, shoot, and climb his way past obstacles and enemies; the game also retains the slide ability which debuted in Mega Man 3. At the end of each stage is a Robot Master boss. Upon defeating a Robot Master, Mega Man gains the Robot Master’s signature weapon, which can then be used by the player in subsequent stages.
Once all eight Robot Masters are destroyed, two separate sets of linear stages must be completed to finish the game. One major addition to the gameplay in Mega Man 4 is the “Mega Buster”, an upgraded version of Mega Man’s arm cannon. By holding down the firing button, the player can now charge a shot, resulting in a blast far more powerful than the standard shot.
This feature was later used in subsequent incarnations of the franchise.
The hero’s dog Rush makes a return from Mega Man 3 with the ability to transform into “Coil”, “Jet”, and “Marine” modes for navigating different environments.
Aside from Rush, two additional support items called the “Wire Adaptor” and the “Balloon Adaptor” also aid the player in reaching areas not normally accessible. However, these hidden adaptors must be found in the stages rather than being awarded for defeating a Robot Master.
Like the Master Weapons, the three Rush modes and the two adaptors are each limited to an amount of weapon power that drains when in use. The character “Flip Top” Eddie is introduced in Mega Man 4. Eddie, who went on to appear in later Mega Man games, provides the player with a random item at designated points in some of the levels