De Blob

de Blob (ブロブ カラフルなきぼう) was originally created as a freeware title for the PC by a group of game design and media technology students in the Netherlands. THQ eventually noticed the game and acquired the rights. They then assigned Blue Tongue, Helixe, and Universomo to develop their own versions for different platforms.

Story
The titular character of the game, de Blob, is the only one who can save Chroma City from the evil I.N.K.T. Corporation. Your job is to bring color and life back to the city, saving it from a horrid monochrome existence. As you absorb color you get bigger, and can paint more buildings before having to refill on color.

Not only can you paint as you wish, but as you paint, the sky turns back to blue and you start hearing music. There are also other revolutionaries trying to help you out by giving you missions to keep you on the right track. By completing missions, you make color energy, which opens gates and forms transform engines, which restore the area you're in.