This is probably the one game that influences me most as a designer. In how it tells a story through miniscule means, absolutely, but more importantly in how it places emphasis on the environment and the player's growing familiarity with the tunnels of planet Zebes. This flourishing relationship between a world and its player is to me stronger and more realistic than most character relationships in both games and other forms of storytelling, simply because it is so much easier to believe in a digital environment than it is to believe in a digital character. There's essentially no uncanny valley to speak of, no complicated behaviour which cannot fully be imitated. A place is a place, and so far I'm seeing much more potential in environment development than in character development in game stories. What I feel for Brinstar and the way I attach memories of the things that happened there to the walls and floors themselves, is the same way I feel for the neighborhood I grew up in. And when I come back there after having moved away, and realize there is a road I've never gone down before and I frankly can't patch together a mental map of where it leads, then I feel like I'm standing in front of a yellow door with a newly aquired Power Bomb upgrade.
I also believe that Metroid is a powerful metaphor for life which trains us in appreciating the abilities we have and finding the places where we can use them to get even better.
The first half of my analysis can be found here! Please enjoy, and the rest will come later.