Heavy Weapon is a cartoonish side-scrolling action game where you control a single tank fighting waves of opponents. Driving to the right over flat terrain at a constant speed, the tank can move left or right while the sky is filled with aircraft such as jets, helicopters, zeppelins, bombers, and missiles. Projectiles need to be avoided or taken out. Some friendly planes will pass and drop power-ups to improve speed, gun power or shield, or provide nukes, rockets, a laser, rapid-fire, or spread fire. During each level, enemies will drop parts of a mega laser weapon. If the four parts are found, an extremely powerful laser beam is added to your arsenal for a short time.