Quayshift — an AI-built endless runner (GPT-6.1 Sol)

GPT-6.1 Sol built this endless runner from a single prompt. This is the real, unedited first result: no human fixes.

Pip sprints through a golden-hour quay, chased by the Clasp. Dodge trams, slide under barriers, jump overhead gates, grab coins and the Flux Magnet, and beat your saved best score.

How to play

1. Press Run game below, then click start or press Enter or Space.
2. Switch lanes with Left/Right or A/D to dodge trams and obstacles.
3. Jump with Up, W or Space; slide with Down or S to pass under barriers.
4. Collect coins and the Flux Magnet, and keep running to beat your best score.
5. On a touch screen, swipe left, right, up or down instead. Press P or Esc to pause and M to mute.

Controls

Click start or press Enter/Space · Left/Right or A/D change lane · Up/W/Space jump · Down/S slide · swipe on touch screens · P or Esc pause · M mute.

Browser and device

• Desktop: works with the keyboard in a current Chrome, Edge, Firefox or Safari.
• Phones and tablets: swipe controls are built in, so touch play is supported; the game has not been tested on every device.
• Needs: WebGL.
• Audio starts after your first tap or key press; M mutes.
• Use the fullscreen button for the largest view.

How it was made

• Model: GPT-6.1 Sol (Codex CLI), extra-high effort
• Build time: 31m 25s, one run, first result only
• Cost: about $0.82–$0.86 at API prices (estimate)
• Fresh folder, no internet, three.js provided

Its rival, Scramble Yard, was built by Claude Opus 5.5 from the same prompt. Play both and decide which you prefer.

Watch the head-to-head

Watch the full build comparison on YouTube (AI model vs AI model, same prompt, endless runner builds).

Get the source code and guide

Want to see how it works and remix it? Quayshift: AI-Built Source + Guide on Gumroad has the untouched game source, the exact prompt, build stats and a 9-page guide with three remix exercises. Or get all four games' source and guides in one bundle. No purchase is needed to play.

Licence and price

Free to play; pay what you want if you enjoy it. Original names and procedural visuals with generated sound. three.js is included under its MIT licence. Your best score is stored in your browser at this page's address, so clearing site data can remove it.

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