Dead Island Definitive Collection contains Dead Island Definitive Edition, Dead Island: Riptide Definitive Edition, and Dead Island Retro Revenge
Dead Island Definitive Edition: Fully remastered version of Dead Island including all released DLC and patches
Dead Island: Riptide Definitive Edition: Fully remastered version of Dead Island: Riptide including all released DLC and patches
Dead Island Retro Revenge: A brand new stand-alone 16-bit game set in the style of a classic side-scrolling action/endless runner within the Dead Island universe