Ape Escape follows the journey of Spike as he tries to stop Specter's evil plan to replace human civilization with a simian society. Specter, once a mild-mannered monkey, has been transformed into a scheming simian using the Peak Point Helmet, and has taken over the Professor's time machine to travel back in time. With Spike's help, the two must navigate prehistoric lands, capture Specter's army, and prevent their evil scheme from coming true.
The gameplay of Ape Escape revolves around capturing Specter's monkeys using a variety of items controlled by the right stick of the Dual Shock controller. Each monkey has unique stats and personalities, ranging from those that barely pay attention to you to those that attack with machine guns and UFOs. The goal is to capture enough monkeys to diminish their effect on history, while also unlocking time attack modes and bonus games like boxing and skiing.