According to Brian Stableford, writing in the Encyclopedia of Science Fiction, the definitive reference on the genre, Camille Flammarion was the first author to present a popular fictional portrait of truly alien life-forms.
While billboard in modern day NYC in Grand Theft Auto might fit right in with the environment, how do you plug a product on an alien planet in the year 2553 in Halo, or do the same in a fictional medieval world filled with dragons and orcs in Skyrim?