Nostalgia is not a personality trait of the games and movies that are considered nostalgic. Much like how "antique" is not a style, but an attribute that applies to some older styles, so does "nostalgia" not represent any particular trait, only the acknowledgment that the material remains beloved by the generation that grew up with it as children.

Sure there are some "nostalgic" properties, and you can emulate a feeling of nostalgia with music - but it's probably just melancholy that's being expressed.