The premise is simple. Whenever a tribe prays to the heavens for the first time, a new god is born. As one of these new gods, the player is tasked with securing their power and spreading their influence. Since gods cannot act outside their influence, they need something to do it for them. That something comes in the form of a giant animal.
Titans come in a variety of species that range the gamut from polar bears to sheep.
When the game begins, the player is given a choice of one of three baby titans. As the game goes on, it is possible to swap one species for another. The newly gained titan will retain its previous physical and mental attributes, preventing the player from having to spend another week developing a titan all over again. A new titan doesn't even know how to get a drink of water until it's shown, but Lionhead has outdone the competition with an advanced artificial intelligence that would put HAL to shame. Without any guidance a titan will wander around and eventually figure some things out on its own, but its amazing what they can learn by example.