Poy Poy is a multiplayer action game in which four players battle each other using various props, such as rocks, logs and blocks of ice in one of six environments. Combat consists of picking up the various props, and throwing them at your opponents. One could also pick up and throw the opponent's character directly.
The game was followed by Poy Poy 2, also released on PlayStation which featured similar gameplay to that of Poy Poy.
Source: Wikipedia, "Poy Poy", available under the CC-BY-SA License.