FusionFall

Cartoon Network Universe: FusionFall was a massively multiplayer online game developed by Cartoon Network and South Korean studio Grigon Entertainment. Under the control of Lord Fuse, Planet Fusion travels through the universe. He is destroying planets by devouring them, and Earth becomes the next target. To do so, he drops Fusion Matter that takes a warped monster-like shape of objects nearby. The goal is to prevent the enemies' plan and defeat them. (Wikipedia, edited)