Executive 1: Hey I got an idea. Let's make a game about exploration with an excuse for a plot and lots of frustration!
Executive 2: Your plans impress me, as does the size of your penis.
Executive 1: I am impressive.
Metroid 2: Return of Samus
Executive 1: That first game was a big success, let's do it again but for the gameboy. Grainier, with less color, but somehow more gameplay.
Executive 2: You could satisfy an elephant, or a whale, or both at once.
Executive 1: It's been a while since we made an actually good game, how about we follow up on that last Metroid game we made.
Executive 2: Penis size joke!
Executive 1: This wears thin quickly.
Executive 1: Prequels are "in" this year (and every year following and preceeding it) so let's make one.
Clown in a Suit: I can juggle 5 balls at once!
Metroid Prime 2: Echoes
Executive 1: I fired the clown, so let's make one of those trendy Dual World type games. Like most sequels to prequels, it'll be harder and weirder, but still somehow fun.
Talking Horse: A Mr. Ed reference? That's low.
Metroid Prime 3: Corruption
Executive 2: Hey, what happened to that well endowed go-getter Executive 1?
Executive 3: He was fired for possessing a dangerously large penis. It was a threat to national security. Let's make a crappy sequel to our two prequels that will enthrall most gamers but enrage one VERY SPECIFIC one with the poor quality and emphasis on shooting instead of exploring.
Clown in a Suit: Even I can tell that's a bad idea.
And so, the story of Metroid comes to a close.
Until the new one comes out and fails to impress a blogger with too much time on his hands.