Here we are, already at the “end” of Donkey Kong: Its fourth screen. By today’s standards, DK is comically short, but four uniquely designed screens was nothing to sneer at back in 1981. Besides, arcade games weren’t after long-term immersive commitments. This was a light snack of a game to see how high a score you could rack up before being unable to keep up with the rising difficulty as you worked through the four looping stages over and over again. You wanted the kind of time sink we expect today from a Skyrim or whatever, you bought a PC and played Wizardry. For a quarter — about 65 cents in today’s money — Donkey Kong offered a satisfying bang-to-buck ratio.

One neat thing about Donkey Kong‘s fourth stage is that it actually lets you “beat” the game. Sure, once you finish this level you loop back to the start, but for all intents and purposes the game places a clean divide between story and play. Subsequent post-conquest loops simply let you experience the story in a more challenging way, but once you’ve blasted through all four levels you’ve witnessed the full Donkey Kong story: Gorilla steals girl, climbs construction project. Blue-collar dude goes to rescue her. Gorilla retreats further up the construction site every time blue-collar dude comes near.

And eventually, we come to this place: 100 meters up, a place from which there is no further retreat. Mario’s pursued Kong all the way to the top of the building being assembled. Pauline stands stranded atop a scaffold at the peak, while Kong stands pounding his chest as a cornered beast with no further tricks up his sleeve. Unlike previous stages, he has no offensive maneuvers here, and he doesn’t move left or right. He is, effectively, on the ropes, seeking sanctuary in the skeleton of the penthouse office.

Of course, he can still smack Mario senseless, so the goal here is to conquer Kong indirectly. You can’t win in a straight fight, so instead you get to turn the tables on the beast and use the level design against him for once.

Fittingly, this is the most “boring” stage layout in the game. Unless you’re simply a thundering idiot and leap off the side of the girders, it lacks the platforming challenges of the past two stages. The ground is stable, flat, and spans nearly the entire screen uninterrupted. The only real threat comes in the form of the Mario-seeking fireballs, which appear in alarmingly large numbers.

But your goal here is different than in the previous levels. You’re not trying to reach Pauline this time; it’s a snap to climb to the top of the girders. But with no ladder leading to her from Kong’s perch, Mario can’t actually reach Pauline this time. The objectives have changed, and instead of its previous race to the pinnacle the game takes on a touch of Pac-Man: You can move freely around the screen now, and your goal is to pass over and gather each of a specific type of collectible. Here, though, the items you pursue aren’t dots but rather rivets holding the structure together.

Sharp-eyed players will notice that the center portion of this structure on every level consists  of the same I-beam flanked by a pair of bolts. Mario’s task, then, is to remove these rivets from the joints holding the central portion aloft, causing Kong’s support to collapse. You accomplish this by simply walking or even jumping over the bolt.

Simply accept the game logic of this all, OK? No, realistically this doesn’t make sense (why doesn’t each girder collapse once the rivet is removed? How is Mario able to grab a bolt while sailing through the air above it?), but, you know, whatever. The goal communicates itself pretty neatly and obviously through visuals, and the level objective does a great job of turning the tables on a grand scale. It works. It feels climactic. And it’s fun.

The bolt-gathering mechanic changes up the nature of the game somewhat. Until now, collecting has been optional: You can gather up Pauline’s lost belongings (purse, hat, umbrella) in each stage for a score bonus, but it’s strictly a points thing. Here, you have to chart a path through a swarm of unpredictable fireballs while also taking into account the dynamic nature of the stage.

See, while this level begins as a wide-open four-tier structure linked by ladders — allowing you to move freely at your whim — gathering up the rivets changes the lay of the land. Each rivet you swipe leaves a gap in the floor that affects both you and the fireballs. You can leap the holes, but you can’t walk over them (Mario hadn’t learned to B-dash yet — it’s very tragic). Neither can fireballs pass over the holes.

This can have both good and bad effects. It’s great when you’re being pursued by eager flames: Simply hop over a rivet and it’ll be stuck at the edge of the hole, fuming at you in impotent frustration like those cops from the next county over every time the Duke boys crossed back over the Hazzard county line. On the other hand, the vanishing rivets causes the fireballs to cluster up dangerously, which can be a real problem when they clump together around a spot you need to pass over to pick up a bolt. The gaps also limit your own offensive capabilities; since you can’t jump or climb while wielding a hammer, the presence or absence of bolts on your current level determines just how widely you can range in pursuit of fireballs to smash.

With all the bolts in hand, Donkey Kong experiences a comical Wile E. Coyote moment as the girders collapse and he’s left hanging in the air for a moment before plunging 15 meters to the lowest level.

But wait! Pauline’s platform is also suspended in midair with no support! Does that mean…?

No. It doesn’t. In a nicely thoughtful touch, Miyamoto designed her perch to be slightly wider than the span of the girder-and-rivet gap below, so it drops down to where Kong had been standing, allowing her to reunite safely with her midget love. Pity Tom Cruise and Nicole Kidman broke up — they’d be perfect as the leads in the live-action Donkey Kong.

Kong himself is defeated but not dead, a divergence from the King Kong source material (and more in keeping with Donkey Kong‘s other inspiration, Popeye). He’s merely stunned. Video games were more humanitarian back in the day, you see. Ostensibly, this leaves Kong free to start the next loop and kick things off all over again. But really, it leaves the door open for the sequel, in which some basic roles become radically reversed.

It’s not hard to see why Donkey Kong catapulted Nintendo to powerhouse status. In 1981, its breadth of variety, crisp visuals, and shifting challenges and objectives outshone anything yet seen in the arcades. Other games matched it in one area or another, but nothing else brought all three of these values together into a single package. For all its relative complexity, its design did an excellent job of teaching the player on the fly from the very opening moment where Kong chucks a barrel directly down into the oil tin to motivate Mario to get moving.

Despite the somewhat weak second level, Donkey Kong remains fun to play more than 30 years later — it’s simple compared to all that it inspired but remains entertaining for its purity of purpose and how well its concepts are expressed. You can see how Donkey Kong would kick off a dynasty of games that continues strong three decades later; its creators are still around, and they’ve never completely lost sight of the design discipline they demonstrated here.