Per Wikipedia: In a distant future, Earth lives in chaos and the only order that rules resides in the Battle Game, where the winner takes control over the world. All battles are fought with mechs called Standing Tanks (ST). A merciless fighter called Anubis eventually becomes the champion of the Battle Game.
Mike Anderson, whose father was one of the many victims of Anubis, refuses to succumb, and trains himself in everything ST-related to stop the current chaos and avenge his father's death. To accomplish this, he must first defeat the Battle Chiefs (Anubis' subordinates).
In the game, the player is the gunner of the ST Falcon and also Mike's partner, who fights against a group of other STs in one-on-one battles. To attack, the player must shoot using the Super Scope. It is possible to shoot rapid shots by holding down the fire button, as well as energy bolts (charged shots). Energy bolts can be shot when an energy bar fills up (this happens when the player does not fire). When the energy bar has filled up, the energy bolt can be fired, though it will consume the energy bar. It is also important to defend against enemy attacks by shooting their fire. Some attacks can only be deflected by firing energy bolts.
The objective of the game is to defeat the rival ST to clear the stage. The damage inflicted on the enemy depends on the spot where the ST has been shot (all STs have some kind of weak point) and how powerful is the shot. The player wins if the rival ST's energy is depleted first. If the enemy depletes the player's energy or if the stage is played for ten minutes, then the game is over, but it is possible to continue the game indefinitely.