Two questions lads.

super does the best job of any game in the series, possibly anywhere, of presenting you with a "nonlinear" world, while secretly being set up to guide you exactly where it wants you to be at almost all times. you get the tightly controlled pacing of a linear game, without sacrificing the player's sense of agency

example: the game goes out of its way to trap you inside lower brinstar/norfair, and keep you there until you get the ice beam. you have to go into norfair to get the high jump; immediately back out to crawl around lower brinstar until you find kraid; immediately head back into norfair proper to get at least the speed booster and ice beam; and only then does it let you freeze your way upward toward the power bombs

after this,the "efficient" non-sequence-breaking choice is to head back to norfair *again* for the grapple beam, but instead they present you with this shiny power bomb door leading directly to an exit, which of course you're going to take. freed from the depths of the world for the first time in hours, you're then free to use two of the game's most powerful tools (power bomb, speed booster) to re-explore the world and discover all the cool shit you missed

metroid isn't just "backtracking;" this piece of super uses "revisiting previous areas" to produce two distinct yet complementary effects. trapping player inside norfair forever, making them keep dipping in and out, creates a sense of active hostility toward that piece of the world -- but by delaying the return to crateria for as long as possible, that hostility is then converted into huge catharsis, when player finally breaks free

to cement this, it changes your crateria theme from rainy ambience to a bright, triupmhant fanfare. utterly perfect

but the real secret sauce: as soon as you the player figure out the "nonlinear" trick, it's flexible enough to let you sequence break it, claiming even more agency for yourself providing you have the skills