The primals are a colourful bunch of characters, Colour is a simple yet successful way of differentiating between environments, and certain hues immediately bring to mind certain geographical regions. Because of this its easy to dream up surroundings such as ice, desert and jungle levels as they're easily associated with a specific hue.
Anyway, enough science! Congratulations to all at Rivet on their hard work and go see for yourself as Rivet Studios' title Primal Rumble is out very soon! Get rumbling!