Ape Escape: On the Loose (サルゲッチュＰ Saru gecchu P) is a PlayStation Portable remake of Ape Escape. The remake features altered controls, due to the lack of a right analog stick on the PSP, as well as some slightly different graphics and mini-games. The remake also features entirley new voice acting.
The story begins when Specter, a white-haired monkey at a monkey park, puts on an experimental Pipo Helmet created by a Professor, which increases his intelligence beyond that of a regular monkey but also twists his mind, turning him evil. Imbued with this new power, Specter gives Pipo Helmets to all the monkeys in the park and sets them loose, having them take over the local laboratory where the Professor and his assistant Natalie are currently building a time machine. As Spike and his best friend Jake arrive at the laboratory, they find themselves transported by Specter, along with all the other monkeys, to the various reaches of time. Realizing that leaving the monkeys to their own devices could rewrite history in disastrous ways, the Professor tasks Spike with finding all of the monkeys scattered across time and sending them back to the present. Spike must also face off against Specter, who has not only built himself an advanced Peak Point Helmet further increasing his own intelligence but has also brainwashed Buzz to his side.