The player must navigate through the mountains, collecting clams. Like the comic strip, they are used as money, in this case to pay the toll to another caveman, Peter, to access the next mountain.
There are two modes of play. The first is along the mountainside, where the user can move all four directions, but must avoid falling off the cliff, slamming into the wall, hitting a rock or a hole, or encountering the creature Grog, who will yell "GROG" and knock the player off the mountain. There is also a green dinosaur that will eat the player's "tire" on contact. The player may enter caves to enter the second mode. The caves are dark except for a beam of light emanating from the player, and clams must be collected without running into stalagmites. At the end of a mountain, there is a bridge to a new mountain. If the player has enough clams, the game continues; otherwise, it is necessary to return to find more clams.