In Gearheads, you put your wind-up toys up against another guy's toys in an attempt to cross the field of play. The first GearMaster to get 21 toys across the opponent's border is the winner.
There are 12 wind-up toys featured in Gearheads, each with different size, speed, and skills. They include Big Al, a bulldozer; Clucketta, an egg-laying hen; Deadhead, a chattering skull; Disasteroid, a slow but powerful robot; Handy, a walking glove; Kangaruffian, a boxing kangaroo; Krush Kringle, a sadistic Santa wannabe; Orbit, a speedy flying saucer; Presto, a teleporting magician; Walking Timebomb, a bomb with feet; Zap-Bot, a wheeled robot with the ability to fry other toys; and Ziggy, a scurrying cockroach.
Some toys are heavy and can push other toys back. Other toys will destroy the objects in their way. Once you release a toy, you no longer control it. Your only control over the toys in the game is where it is launched and how far it is wound.
There are three modes of play in Gearheads: one-player tournament, human versus computer duel, and human versus human duel.
In the one-player tournament mode, you are given four toys and are pitted against the computer, who also has four toys. Get 21 toys across the computer's border, and you advance to the next level. Tournament players start each tournament with three lives. Each time the computer gets 21 toys across the field before you do, you lose one life. After every third level, there is a challenge level where you can earn additional lives. In challenge levels, however, you only get one toy.
In human versus computer duels, game play is similar to that of the tournament, except you can choose to play with as many or as few toys as you want. Duel mode also features level selection, so you can choose which battlefield on which to fight. Duel mode also allows for power-up items.
Human versus human duels are like the human versus computer duels, except two human players square off with a box of toys. Using keyboard controls, both players play simultaneously on the same screen.