Complex sentence: Survival Instinct is an upcoming first-person shooter video game developed by Terminal Reality and published by Activision, based on the television series "The Walking Dead", unlike the video game by Telltale Games which are based on the comics.
Split into simpler sentences: Survival Instinct is an upcoming first-person shooter video game developed by Terminal Reality and published by Activision. It is based on "The Walking Dead" television series, in contrast to the video game by Telltale Games, which is based on the comics.