With the Mother Brain defeated, Metroid ends up back again where it began. The final sequence of the game doesn’t involve combat or exploration but rather a tense escape sequence up a seemingly endless shaft — an echo of the game’s first sprawling vertical area, the one that definitively set Metroid apart from a legion of left-to-right side-scrollers.

This is no straightforward reprise, however. That early tunnel was a teaching experience, helping players come to grips with Metroid‘s unconventional design. A host of patrolling enemies imparted the value caution, while the seemingly unending upward scroll instilled patience and persistence. The wide platforms didn’t simply force players to navigate by zig-zagging horizontally within the ascent, they also provided a sort of safety net in the event of a slip-up. You might fall and lose some progress, but not much.

This shaft, on the other hand, affords no caution. It lacks enemies of any kind — after all, Mother Brain is dead, so what’s the point? — but that doesn’t make it easy? Samus is racing here to escape the Zebes underground before the space pirates’ spiteful self-destruct countdown ends, giving you roughly 90 seconds to make the climb and escape.

This is much more easily said than done, however, because the shaft contains only itty-bitty platforms. The only surfaces in the game smaller and more precious than these tiny things are those three single bubbles floating in a line deep inside Norfair — and the worst thing that could happen if you missed one of those is that you’d fall into lava and lose a bit of health. A single slip here is likely to send you plummeting all the way back down to the start. You can only afford a couple of minor slips before you’ve wasted so much time there’s no hope of reaching the end.

The escape sequences tests your understanding of Metroid‘s physics like nothing else in the game. For most of the adventure — especially since acquiring the Screw Attack — Samus’ aerial summersault is one of the most important and powerful skills in the game. But here, it’s absolutely deadly, because she’s much harder to control once she starts spinning.

To survive here, you need to fight your programming and resist the urge to spin. By leaping straight into the air, Samus will remain upright and follow a much tighter arc with her jump. This means you have much less lateral range when you leap, but the platforms here are arranged in such a way that you don’t need to move much to either side. After hours of wild, weaponized leaps, the secret to survival is to move cautiously and deliberately, employing the full range of Samus’ skills.

Once you get the rhythm down, this sequence turns out to be remarkably easy. Keep your nerve and move with care and you’ll reach the top of the shaft and escape to freedom, where you’re visually graded on your efficiency. Take too long to beat the game and Samus turns her back to you in despair; play quickly enough, however, and she reveals her shocking (in 1986) secret: A feminine pronoun. Play even more effectively and you’ll be able to control Samus in her unarmored female guise.

Play really well and she’ll strip down to a tiny two-piece bikini for some 8-bit titillation. Nintendo was pretty progressive, making Metroid‘s protagonist a woman, but… well, baby steps.

No, you can’t play as bikini Samus. No matter how much you wanted to as a 13-year-old.

Now that I think about it, Metroid kind of did the New Game + concept, huh? Once you beat the game, you can start over with every item and power-up in your inventory save Missiles and Energy Tanks. The alternate character sprite is a sort of hidden bonus to reward players who try to make better time through the game by improving their time in subsequent cycles, but the simple fact that you can start from the beginning with both a more powerful character and a clear sense of the labyrinth’s layout is enough to motivate some players.

On the whole, this trip through Metroid honestly surprised me. I think I’ve bought into the general sentiment that it’s a clumsy, dated, badly made, and nigh-unplayable mess — but really, that’s not true. Certainly Metroid has its rough spots, and you can definitely see the limits of both 1986’s technology (in the glitches and repetition of scenery) and game design (in the poorly communicated mechanics throughout the middle stretch of the adventure).

Yet on the whole, Metroid‘s powers and world are at once inventive and effective. The fact that the tools to range further into planet Zebes are integral parts of Samus’ arsenal rather than standalone keys really sets Metroid apart even now. The idea of exploration expanding organically as a function of the protagonist’s growing skills is one of the most compelling forms of game design in existence, and I think it’s safe to say that Metroid didn’t just pioneer it — it nearly perfected it in one go.

Nearly. The game does have its flaws, no doubt. But think back to the first portions of the game, the way it’s so deliberately structured to guide you to the items you need while holding you back from areas you’re unable to deal with — that’s some remarkably mature and sophisticated game design. I really feel like game design truly came into its own in the second half of the ’80s, and Metroid was one of the key titles that helped lead the way. Maybe it wasn’t amazingly revolutionary on its own, but as part of a larger movement toward more complex and sophisticated design, it deserves a place in history.

Plus, it set the framework for Super Metroid. That alone makes it worthy of admiration.