OmegaX: God forbid and adult could enjoy a game for its gameplay instead of having to watch hours of cutscenes and scripted scenes in a generic middle east setting.
Also, if you think the Metroid Prime series is kiddie then I pity you.
scampywiak: Metroid, a character based on some Japanese developer's infatuation with Kim Basinger, yes, much to discover there.
And for game play, I'm intrigued by the narrative depth of both Zelda and Mario, after countless iterations, they just keep on giving. Mario - he still jumps, and never disappoints as a cliche Italian jumping dude. And Link, always the emo blonde. So different each time, so innovative. Nintendo, what would we do without their innovation?
Metroid is a jelly fish looking alien, I don't see the resemblance to Kim Basinger :P Are you saying that if a character is based on the looks of a real person then it isn't a good character or something? I don't see your point if you even have one. Leliana from Dragon Age is based on a porn actress, that must mean DA:O is crap, right?
So for you gameplay is the same as narrative? Maybe for point and click adventure games or interactive movies that would be the case. Good story is nice for certain genres but it's hardly required for others. Otherwise Doom would the worst game ever.
If you refuse to look past the characters instead of actual gameplay mechanics, and level design the that's your loss.