Impossible Creatures

Impossible Creatures is a 2003 steampunk real-time strategy game developed by Relic Entertainment and published by Microsoft Game Studios. Its unique feature is that the armies used in gameplay are all created by the player, and involve combining two animals to make a new super creature with various abilities. The concept was inspired by H. G. Wells' novel The Island of Doctor Moreau. The player-created armies are capped at 9 creatures; each one is a combination of any two animals from a list of 76 (51 with no downloads). Many animals possess inherent abilities and players can plan units and armies to combine multiple such abilities or compensate for weaknesses. There is an extensive single-player campaign as well as online multiplayer functionality with different game modes, add-ons, custom maps, mods, and scenarios.