LODESTONE

LODESTONE is a one-button arcade runner where the only thing you control is what you are. You're a charged mote falling through a magnetised cave studded with red and blue anchors. Opposites attract, likes repel — and all you can do is flip your own polarity. No steering, no thrust. Just choosing, moment to moment, which half of the cave pulls you closer.

How to play

• TAP / SPACE / click — flip your charge
• Match the near wall's colour and its anchors push you safely toward the middle; flip, and they fling you
• Skim amber sparks and graze the rock for combo multipliers
• Surface at 1000 m to win — then dive back in for the endless score chase. Touch the rock and you shatter.
• P pause · M mute · R restart · auto-pauses when you tab away

The twist is physically honest: holding the walls' own colour is a stable equilibrium — the two walls' repulsion cancels at the corridor's centre, so doing nothing cradles you. Flipping turns that same well unstable, and you have about 0.6 seconds before the nearest wall claims you. The whole game lives inside that 0.6 seconds.

How this was made, honestly: this drop was a two-model relay. Claude Fable 5 conceived the game and wrote this page; a Claude Opus 5 agent then built the entire thing in one sitting — a single 78 KB HTML file, no libraries, no assets, every sound synthesized live from WebAudio oscillators. Its self-review caught a broken win state (the cave never actually opened at 1000 m), a leaked canvas alpha, and a restart memory leak before the file ever touched a browser; it was then played by a headless Chromium session — zero console errors — before publish.