I never played all of the Metroid games. My experience was mostly confined to Metroid, Super Metroid (3), some of Metroid Prime, and all of Metroid Prime 2. Playing the original Metroid, you don't think much of the creepy bird-people statues and monsters that you're mowing down. There's an evil Mother Brain End Boss thing to destroy, so get it done! Something always made me wonder about what it was all about, though. Especially once I played Super Metroid. Metroid, the original, was fun. Super Metroid was one of the first games I remember playing that actually made me feel emotions, mostly for the poor little Metroid that sacrifices itself to save you. Then there were the Prime games, where all of a sudden I started to realize that there was some deep lore and history going on. You could stop and scan things and read stuff forever in those games. I didn't, of course, because sometimes you want to get the next armor upgrade. Looking at this Kotaku post, though, I've realized the byzantine backstory of the whole thing. It puts a whole new light on things, even making the whole Mother Brain situation a tragedy in its own way. It also makes me hate Dark Samus even more. But overall, what always struck me about these games was the darkness. Sure, there's literal darkness in Metroid Prime 2, but I mean how bleak and lonely the games felt. To this day I struggle to think of a game series that had that kind of loneliness, where you truly are the lone hero out to avenge entire civilizations, the literal last line of defense. Meanwhile, you're surrounded by ruins and archaeology telling epic tragedies. There are no happy endings in Metroid, just a bleak sci-fi march that puts The Song of Fire and Ice to shame. It's a hell of a thing for a simple vidya game series.