Here's a condensed version of the above charts, showing what the whole of the game looks like in terms of item dependencies:

Fairly straight-forward. A little bit of back-and-forth, but the Chozo Ruins area is linear and quite accessible, so it's not too too bad.

Psst... Looking for the spoiled version? Click here.

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.

Started rocky, ended... headache-inducing. Totally not a Metroid game though, nope. No Metroids to be found here.

Here's a condensed version of the above charts, showing what the whole of the game looks like in terms of item dependencies:

The escape through Phazon SRX88 will have a number of areas blocked off.

The only way to access SRX88's Phazon Dimension counterpart, is to restore access to your ship and fly to SRX88, then finding a portal there.

As soon as you get your Suit, you'll find a portal leading back to the "normal dimension", but you'll not be able to open the doors without Power Bombs. Furthermore, you'll still take damage in the Phazon Dimension. At this point though, you have a number of options available for you to explore, and different directions you can go. And plenty of Metroids to kill.
I love that feeling of "Okay, you have all your stuff back, and you've uncovered how this game works. Now the rest is open to you. Have fun!" in games. Even if the first half of the game so far has been fairly linear, that open feeling feels earned.

Well this is a surprise!
The Black Zero Suit is actually required. Collecting it will unlock a Save Station later on that will restore all your energy, which is the only way you can survive in this "dark world". You'll see a couple of other Metroids, but you still don't have your suit just yet, so you can't even scratch them. To paraphrase AI Adam, "If you see [them], just run."
The sequence ends once you've restored your suit in the dark version of Trozodia.

Much like in Zero Mission, there's a ZSS section. Unlike ZSS, you could run into Metroids you can't damage (and you'll just have to leave them for later). You can also find your ship, but you'll get a little cutscene saying you need at least 35 Metroids killed and your Suit restored, before you can fly it again.