Though its gameplay is similar to its predecessors, Ape Escape 3 features new changes to the series. The game allows the player to choose between a playable male character (Satoru) and a playable female character (Sayaka) at the beginning of the game (they play the same, though some story cutscenes differ). It centers on one of the two playable characters venturing throughout television programs to capture invading monkeys. There are now 442 monkeys to capture in this game. While there are less gadgets in this game than previous entries, a new feature in this game is the ability to morph into different outfits through a device built by Aki. Another addition to the game is "Monkey Steal!" If you attack a monkey too much not only will it try and face you head on, it may even steal a Gotcha Gadget. If that Gadget is the net, the player may get caught and will be brought back to the hub (The game treats you as though you had used Escape by letting you keep all the monkeys that were caught, returns any stolen items, and you do not lose a life from it). The stun club and the monkey net are the only gadgets that can get stolen. Also unlike Ape Escape 2, there is monkey radar data for Specter and the Freaky Monkey Five. This also doesn't have the Magic Punch unlike the other Ape Escape Games.
Source: Wikipedia, "Ape Escape 3", available under the CC-BY-SA License.