While the base game discs remain playable (at used prices that have skyrocketed), the DLC servers were turned off. If you did not download the Character Pack or Simulator Missions back in 2010, you cannot legally access them through official channels today. Hence, the archival community turned to PKG files.
However, a licensing nightmare struck. Within months, the DLC was pulled from the store. It became a digital ghost, a "pkg" file whispered about in modding forums and retro gaming circles. To find a PS3 today with those files legitimately installed is like finding a mint-condition Amazing Fantasy #15 . marvel ultimate alliance 2 ps3 dlc pkg