To defeat the boss, the player must stand on the button long enough to make the Gapsule to try crush him/her with one of his spike-ball arms. If the player jumps out of the way quickly enough, Gapsule will hit itself instead, dealing a hit in damage. After dealing itself six blows, the boss explodes, and the player proceeds to Act 2.
This was the final boss of the Sonic & Knuckles game in the version of Sonic Jam for the Game.com. Like all other bosses, it has become much slower, and less difficult to defeat.