New Yorkers get all the fun Nintendo stuff, don't they? Case in point, this Saturday the Nintendo World Store in Rockefeller Plaza is hosting a pre-release party for Mystery Case Files: MillionHeir for the Nintendo DS, developed by Griptonite Games for Big Fish. Children of all ages are invited to hunt for clues, search for hidden objects, and interact with live performers as they attempt to solve the disappearance of millionaire Phil T. Rich - Filthy Rich for those of us fluent in bad pun. There'll be food, drinks, prizes, and a chance to purchase the game two days earlier than everyone else, which I suppose is a reward for participating in the interactive sales pitch event. The mystery party runs from noon until 2pm Saturday, after which parents can pretty much leave their children to wander about the Nintendo World Store unattended while they go grab a latte.