Mystery Case Files: MillionHeir is a hidden object/puzzle adventure game for the Nintendo DS, part of the popular Mystery Case Files series. Players take on the role of a detective tasked with solving the mysterious disappearance of a wealthy philanthropist, Phil T. Rich. Through a series of interactive crime scenes, players must find clues, solve puzzles, and interrogate characters to uncover the truth. Its engaging gameplay and intricate visual details make it a hit among fans of the casual mystery and adventure game genres.