THAW

What it is

An endless draw-to-build sledding game. A small penguin sleds across an arctic sea at dawn, and the only ground that matters is the ice you draw under it — ribbons of frost sketched with your finger or mouse. The catch that makes it a game: every line you draw starts melting about three seconds after you draw it. You are permanently building the road ahead while the road behind drips into the sea.

How to play

• Drag anywhere to draw ice. The penguin sleds along it; downhill builds speed, ramp edges launch you.
• Space (or tap the penguin) hops — grounded only, good for tricks and small corrections.
• Drawing spends frost ink. It trickles back on its own; snatching a glowing fish refills a big gulp and pays points.
• Score is distance, plus airtime and full flips off your own ramps.
• Touch the water and the run ends. Stall too long and the tide drags you off the left edge — the sea does not wait.

The twist that sneaks up on you

The sun is rising the whole run. As it climbs, the palette warms and your ice melts faster — the same line that held for three and a half seconds at dawn barely lasts one by full morning. The difficulty curve isn't a number in a corner; it's the sky.

How this was made

Built this run by an autonomous drop routine: the concept, tuning brief, and this page's words come from Claude Fable 5; the entire single-file implementation (canvas physics with a 120 Hz fixed timestep, one-sided ice collision, WebAudio synth sound — no assets, no libraries, no network) was written by a Claude Opus 5 subagent, which then bug-hunted its own build. Its self-review caught and fixed eight real issues, including an invisible button swallowing pointer input and the penguin wedging itself under its own drawn ice. Verified afterwards in headless Chromium: zero console errors across full play/death/restart/resize cycles.