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An open world at 256 × 240

When Nintendo started on Breath of the Wild, the first playable version was not 3D at all. It was a flat, top-down game in the style of the original NES Zelda, built to find out whether the physics and the chemistry were fun before anyone modelled a single mountain. I asked for the same thing, in one line at half past four on a Sunday morning:

seeing as how botw started out as a 8bit prototype to get the physics, chemistry etc right.... can we do the same? create a NES style open world game?

Forty minutes later there was a game. Four hours later it had a name, WILD 8, six quests and a boss, and it is the best thing an agent has built for me so far.

The chemistry is the game

A top-down 8-bit screen: a small green-capped hero on a grass field with signposts and wooden crates, a campfire on a patch of dirt, and orange flames spreading along the edge of a grey rock slope toward the top right. The HUD shows three hearts, a bomb item, four empty orb slots, CLEAR, DAY and a wind indicator
The first version, flat. The grass at the top right is on fire, and the little flag in the corner is why it is burning toward the right.

Every tile knows whether it burns, how long, and what it turns into. Fire spreads to its neighbours with a chance weighted by the wind, so a grass fire runs downwind and dies out against it. Grass burns to ash; in the snow it burns back down to dirt. Electricity flows from crystals through water and through anything metal lying on the ground, so a crate can be a wire. And in a storm, lightning picks metal near you seven times out of ten — which is the exact rule that makes you unequip your sword in a thunderstorm in the real game.

None of that is scripted per puzzle. The four shrines, the updraft you glide on above a campfire, and the boss fight at the end all use those same few rules.

Then it got height

The flat version had a problem that no amount of tuning fixes: in a game about climbing things, there was nothing to climb. After two rounds of playing it I said so:

why dont we just do add a 3rd dimension? but nothing polygonal, just minecraft style. 8bit but with height. everything can stay 8bit, even the old man can stay a sprite

The same 8-bit world rendered as 3D blocks from a tilted camera: a tall dark tower with a glowing orange grid pattern and a blue light beam on its top, a green-capped hero gliding under a yellow paraglider over the grass beside it, a slime and a treasure chest below
The same world a couple of hours later: every tile is now a block with a height, the characters are still flat sprites, and the tower is climbable.

The simulation underneath did not change. The map is still a 160 × 128 grid of tiles; each one simply gained a height, and three.js draws the grid as blocks with the same 16-pixel NES textures on every face. The hero, the slimes and the old man stayed paper-thin sprites that turn to face the camera. Climbing now means climbing an actual wall, with stamina that drains only while you move — which took three tries and one bug report to get right.

Breath of the Wild in half an hour

Asked for more guidance, it did not add signposts. It went and copied the way the real game guides you: a tower that reveals the map, a light beam over whatever you are looking for, an old man by a campfire who has more to say than he lets on. Then, asked for more game, it compressed the main story into six quests:

1
The Isolated Plateau — the tower, the glider, and a way off
2
Seek the Elder — a village with houses you can climb
3
Free the Four Spirits — four shrines, any order
4
Captured Memories — find where three old photos were taken
5
The Hero's Sword — through the Lost Woods
6
Destroy the Blight
A black menu titled MEMORIES with three sepia photographs of blocky 8-bit landscapes labelled THE LONE PEAK somewhere west, THE STORM BRIDGE somewhere south and THE BURNING SANDS somewhere west, and the text FOUND 0 OF 3 — stand where a photo was taken to remember
The three photos are not drawn. The game renders them from its own world at start-up, from the spot where you have to stand.

The Lost Woods are my favourite piece. The forest is fogged, and straying from an invisible path sends you back to the entrance. The guide is your torch: its embers drift along the path ahead of you — carried by the same wind that spreads the fires.

A hero holding a torch in a foggy forest of blocky trees, two lit braziers behind him, a thin line of orange embers rising ahead, and two messages: THE FOG IS THICK. FOLLOW THE EMBERS OF A LIT TORCH, and THE FOG THICKENS... YOU ARE STRAYING. TURN TOWARD WHERE THE EMBERS DRIFT
The fog closes in as you stray, and the embers lead you back.

The first version of this was unplayable, and it is the best bug of the morning. I reported walking in with a lit torch and seeing only three glowing dots before being sent back. The fog was measured from the camera, which sits fourteen blocks behind the hero, so it hid the entire world including me. The agent's own screenshots had missed it because the fog fades in, and the test only captured the first frame. After the fix, a bot that did nothing but follow the embers walked from the entrance to the grove without being sent back once.

The Blight at the end wears an elemental shell, and a blade just bounces off it. The weakness cycles — a bomb for the orange shell, fire for the blue one, and for the yellow one you throw a metal crate at it — and only a cracked shell lets the sword in.

A stone castle courtyard in 8-bit blocks with a boss bar reading THE BLIGHT and YELLOW SHELL: THROW METAL AT IT, a glowing stunned creature behind a portcullis, eight hearts and four filled orbs in the HUD, and a message: THE BLIGHT'S SHELL CRACKS! STRIKE IT WITH YOUR SWORD WHILE IT IS STUNNED
The whole chemistry set, as a boss.

How it was made

Nine messages from me, each one mostly a bug report from actually playing: climbing cost nothing while standing still; it rained and thundered far too much for the start of the game; the water shrine made no sense; I got stuck in the old man after falling from the tower. classic you. The agent fixed each one, and verified the fixes by driving the game from a headless browser rather than asking me to try again.

code
3,271 lines of JavaScript, plus three.js for the blocks
assets
none — every tile, sprite and sound effect is generated in code
resolution
256 × 240, the NES screen, scaled up
world
160 × 128 tiles, five regions, weather per region
built
one Sunday morning, 04:34 to 08:30
length
about half an hour — the agent's estimate, nobody has timed it

Still rough

It needs a keyboard — there are no touch controls, so it will not play on a phone — and the half hour is a guess. The quests are there because I asked for them, not because anyone balanced them. If you get stuck, press P: there is a developer menu with eight save slots, one per chapter, and a god mode I will not judge you for.

It rhymes with Diorama from earlier this week — another agent, another Zelda, the opposite direction. That one went for how the Switch remakes look. This one went for why the original works.

Play WILD 8in the browser, WASD + J K L Stuck?P opens the save slots WILD 8 on itch.iosame game, with comments