Players move through horizontally scrolling stages, firing at soldiers, vehicles, creatures, and environmental targets while rescuing prisoners of war. The objective is to reach each stage boss, survive its attack patterns, and continue through the campaign.

The standard arsenal includes a handgun, grenades, and temporary heavy weapons found in crates or dropped by enemies. Vehicles such as the Metal Slug add armor and mounted firepower. Stages introduce branching-looking encounters, transformation effects, and escalating boss battles, while credits and continues determine how long a session lasts.

Conserve heavy weapons for dense enemy formations and bosses rather than firing them immediately. Learn where prisoners, enemy ambushes, and weapon crates appear so that you can approach dangerous screens with the right equipment.

Use grenades at close range or against clustered enemies, and keep moving when enemy fire fills the screen. In vehicles, use the vehicle's firepower aggressively but remember that the machine can be destroyed; exit before a doomed vehicle costs a life.