SLIDARIA

Play SLIDARIA free in your browser: a snake game with nothing to download and no sign-up. It takes after Singleplayer. The game is AI-made: Opus 5 wrote it, and the prompt is published below.

About SLIDARIA

SLIDARIA is a snake arcade game for one player against a lobby of bots. You are one glowing snake in a circular arena shared with twenty-six others, and length is the only score. Eat the drifting orbs to grow. Nothing happens when another snake runs over your tail, so the only things that kill you are putting your own head into someone else's body or into the arena wall, and every fight comes down to who crosses in front of whom. When a snake dies its entire body collapses into a pile of food, which is why the biggest gains come from kills rather than grazing.

Steer with the mouse. Hold the left button, the right button or space to boost. Boosting burns your own length and drops it behind you as food, so a chase costs the hunter as well as the hunted. On a touchscreen, drag anywhere to steer and hold a second finger to boost.

Every run reseeds the arena. The twenty-six rivals get new sizes, colours and temperaments, some cautious, some that will circle you the moment you outgrow them, and the leaderboard is different each time. Fourteen colourways unlock as your best length climbs.

One tip: big snakes turn wide. When something huge commits to a turn, cut inside it. That is the whole game.

How was SLIDARIA made?

Creator

Drakoniux

Model

Opus 5Anthropic

Effort

Max

Tokens used

5,360,000

Build time

345 min

The prompt behind SLIDARIA

Build a snake arena game from scratch, using a lot of different agents - spawn different agents, sonnet and opus, for different tasks. Make it fast while keeping the quality, make it sleek, and make it feel good to play. The user named it SLIDARIA.

Built by roughly twenty-five agents across four parallel waves against a written interface contract (SPEC.md) that fixed every global, function signature, field name, DOM id and the world's tick order before any code existed, so twelve module agents could write twelve modules blind without integrating into a mess. Opus took the algorithms - the fixed-capacity ring-buffer spine, movement and growth, world, collision and death, the bots, the renderer and the game loop - and Sonnet took the craft: palette and skins, sprite pre-rendering, HUD, the WebAudio synth, the HTML and the CSS. Snake bodies are drawn as four strokes of one path rather than hundreds of circles, which is what holds twenty-six snakes at sixty frames per second.

A headless harness drives the real page: tools/shot.html poses any scene for a screenshot, and tools/soak.html runs the world with the renderer stubbed, reporting step cost, the food economy trend, deaths by cause, kill credit and path invariants. That is what found the load-bearing faults, none of which were visible in the code. The camera's zoom exponent exactly equalled the snake's turn exponent, so the two cancelled and screen-space turn radius was identical at every size - the genre's whole difficulty curve was mathematically absent while each formula looked correct on its own. The food economy inflated at 121 orbs per minute. No bot had ever died at the wall. And bot path sway had been tuned by amplitude when lateral swing is v*A/(2*pi*f), so frequency was the real lever and the sway was invisible on screen.

Then play-tested and cut back. The user disliked the deliberate imperfections - a lateral head bob on every snake and a slow sway on the bots' steering, both added so motion would not read as machinery - and asked for smooth, straight travel; removing both changed the arena's kill rate and attrition not at all, so the wiggle had been paying for nothing. Background music was turned off by default, and bodies were lengthened by half again after the user found that encircling another snake was near impossible at the original length.

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Version 1.3 · updated 2026-09-07

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