Being inspired by Gamemaker's Toolkit's first season of its mini-series Boss Keys, which is a series that looks into the design philosophies of Zelda dungeons in terms of layout, I decided to do something similarly for the Metroid series. This idea was fueled by things like item randomizer algorithms and 100%-speedruns, because I wanted to find a way to chart out the areas of Metroid in an attempt to facilitate pathing and maybe even help Metroid fangame makers to think about design and gating in their games.
AM2R, the infamous Metroid fangame that made Nintendo go DMCA-crazy. A lot of praise to the game is centered on it being a very close recreation of the original in terms of layout and design, but adding of course some new and modern features and upgrades. Let's see just how similar the two charts are in terms of progression.
For the sake of simplicity, I'm only regarding the vanilla layout of items as of v.1.4.1 (for now, will update to latest), but also mixing in the one major blockage from New Game+ Mode: the total number of Metroids needed get past the open area of the game.