Using the LithTech engine, Monolith produced the sequel to the popular to Aliens vs. Predator in 2001, to rave reviews. The balance problems in the first game of the series were worked out, and the multiplayer mode has won numerous awards. Aliens vs. Predator 2's uniqueness are the three species (though four teams, since there are two human teams): They are very different, but play is also well-balanced. The mythos and atmosphere of the Alien and Predator movies is also faithfully reproduced, making for a gameplay that is at times terrifying.