Montana Max has captured Buster's friends, Babs, Plucky, and Hamton in an attempt to dampen Buster's spirits. To make matters worse, Monty has summoned henchmen, who have escaped from Wackyland. Now, it's up to Buster to fight Monty's henchmen and save his friends.
Similar to arcade-style games like Bubble Bobble and Mario Bros., each level takes place in an arena, and in order to clear the level, all the enemies in the arena must be destroyed. The D-pad controls Buster, pressing the A button makes Buster jump, and pressing the B button makes Buster throw a ball.
There are three different types of balls Buster can throw; a football, a soccer ball, and a baseball. Pressing the B button by itself makes Buster throw a football, which travels quickly and can bounce off the floors and ceilings. Pressing Down on the D-Pad and the B button at the same time makes Buster kick a soccer ball, which travels at a moderate speed and can drop off the edges of platforms. Pressing Up on the D-pad and the B button at the same time makes Buster throw a baseball, which travels at a slow speed horizontally, and explodes when it hits a wall. This explosion is quite large and will stun all enemies within its range.
To defeat enemies, Buster must stun them by throwing a ball at them. Then he must walk up to them so he can smash them with a hammer. If Buster gets hit by an enemy, he loses a life. The game is over when Buster loses all his lives and continues. If Buster hits A UFO, it will drop a power-up he can use. Carrots will temporarily make Buster throw his balls faster, gems will temporarily make Buster invincible, shoes will temporarily make Buster run faster, clocks will temporarily stop all the enemies, Buster heads will give Buster an extra life, and tokens will give Buster a continue.
There are eleven worlds (Inside Acme Looniversity, outside Acme Looniversity, mhe Moon, the Acme Looniversity Bell Tower, the Hollywood sign, the Studio, the Haunted Mountain, the Circus, the Haunted Castle, outside Monty's Mansion, and inside Monty's Mansion, respectively), with the first ten having four levels each. In these levels, Buster must stun and destroy all of Montana Max's henchmen. Clearing a world awards a password to return to the next world at a later time.
After clearing the first ten worlds, Buster comes face to face with the final boss, Montana Max, who is controlling a giant robot shaped like Dizzy Devil. To defeat it, Buster must throw balls at Monty until his health bar is empty, while dodging Monty's henchmen, as well as the lasers the robot fires at him.