Impossible Creatures

This mode consists of 15 different missions, spanning over a group of islands in the South Pacific known as the Isla Variatas, indicating the variety of environments presented to the player, ranging from jungles, deserts, or Arctic regions. The protagonist Rex Chance is required to collect animal DNA throughout the campaign in order to add more animal varieties to his army of combined creatures.

There are three game types available during multiplayer mode, which allows for up to six players at once.

Dr. Eric Chanikov (voiced by Lee Tockar) was one of the brightest scientific minds in history, but after a failed experiment causes the Tunguska Event and kills his wife, he goes into willing exile at a chain of remote islands. There, he reports the creation of the Sigma Technology, a method which makes it possible to fuse two creatures together into a single organism. These reports are ignored by the scientific and mainstream communities.

In 1937, believing that his last days are upon him, Chanikov sends a letter to his son Rex (voiced by Lee Tockar) asking him to visit. Rex, a disgraced war reporter going by the name "Rex Chance", travels to the archipelago. Discovering that his father died at the hands of the evil tycoon Upton Julius (voiced by David Kaye), he vows to avenge his father's murder. He is assisted by the late Chanikov's assistant Dr.

The game was originally called Sigma: The Adventures of Rex Chance. According to early previews, players had to tranquilize creatures and bring them back to the base to collect their DNA. In the final product, though, it is enough for Rex to shoot a creature to collect its DNA. This only applies to the single-player campaign; in a regular multi-player skirmish, all creatures are already available.

Although it would not be released on Steam until 2015, Impossible Creatures was one of the first titles that Valve used to demonstrate Steam in 2003. This was probably due to Valve and Relic’s close relationship; as both had worked with Sierra Online.

The game received "average" reviews according to video game review aggregator website Metacritic.

Maxim gave it a score of eight out of ten, saying that "Once you get past all the gamesmanship, you can concentrate on bitch-slapping Mother Nature by creating twisted beasts that would make Jack Hanna brown his khakis." However, The Cincinnati Enquirer gave it three-and-a-half stars out of five and said that its gameplay "doesn't match the title's ingenious premise." Entertainment Weekly gave it a "C", saying, "If most real-time strategy titles are elaborate versions of rock-paper-scissors, Impossible Creatures is the world's most sophisticated game of rock."