The gameplay of Invizimals has been compared to the Pokémon series, involving players capturing and raising different species of creatures, and allowing the player to battle with them, either against an AI or with others using the PSP's wireless abilities. Unlike Pokémon however, Invizimals requires the player to hunt and capture these creatures within the real world, using the concept of augmented reality, a camera attachment for the PlayStation Portable, and a physical "trap" square-shaped device used as a fiduciary marker. These monsters are spawned at different environments (determined by colors of surfaces and time of day), and the trap is used to capture the monsters. Once captured, players are able to raise and level their monsters, and allow them to learn different attacks that can be used in battle. Players can also use the trap to view their monsters, and take pictures of their collection.
Source: Wikipedia, "Invizimals", available under the CC-BY-SA License.