Doubutsu Banchou

Eat or be eaten! Assume the role of an animal in it's early stages of evolutionary development. As your animal instincts take over, you will boldly traverse hostile environments, savagely stalking your prey to assert your place in the animal chain of power. Will you have what it takes to become the new king of beasts? The game started development on the Nintendo 64, but went unreleased, being later ported to the Nintendo GameCube. A prototype of the Nintendo 64 version has been found

In the land of the Cubivores, the beast known as the Killer Cubivore reigns at the top of the animal food chain. This powerful tyrant and his gang of cronies have gorged themselves on the essence of the land, known in the game as "Wilderness", so much that they have absorbed some of it into themselves. Meanwhile, nature has begun to fade away, becoming drab and infertile, and the number of beasts has declined. The user-named protagonist has taken it upon himself to become King of All Cubivores, in order to challenge the Killer Cubivore and restore the Wilderness to the world.