The "Spore" alien population is exploding, boding well for the September launch of the latest brainchild of computer game legend Will Wright.

Electronic Arts-owned Maxis Studio released "creature creator" software last month in the hope that aspiring "Spore" players would bring a population of aliens to life in time for the game's premier.

The response astounded even Wright, maker of the world's top-selling computer game "The Sims."

"I was really hoping we'd get 100,000 creatures by September and a million by the end of the year," Wright said Monday while demonstrating "Spore" on the eve of the Electronic Entertainment Expo video game trade show in Los Angeles.

"We hit 100K in 22 hours and a million by the end of the first week. The numbers are just blowing us away."

A week ago, the number of creatures in the "Spore" database exceeded the number of known species on Earth.

"It took them 18 days to reach the number of creatures on Earth and, by some accounts, it took God six days," Wright joked during a presentation onstage at the vintage Orpheum Theater.

"Spore" lets people dictate the genetic development of animated characters in a mock universe.

"You are given this God-like power," Wright told AFP in a recent interview at his Maxis office in Emeryville, California.

"You can create ecosystems, biospheres ... We try to make it real science."

Players start as microscopic life forms competing for survival in primordial ooze and work their way onto land, where they evolve into creatures that build civilizations and rocket into space.

Creatures can be made to have scales, fins, wings, claws, extra appendages, additional eyes, or body parts in unexpected places.

The online game's programming gives characters artificial intelligence and figures out how they should walk, laugh, dance, fight or do other things based on what they look like.

Creatures pass on virtual genes to their progeny and build civilizations with cities, governments and economies.

In a computer game first, "Spore" worlds will be inhabited by aliens made by players instead of professional video game programmers.