PIPISTRELLE

You are a pipistrelle bat in a limestone cavern at night, and the screen is telling you the truth: you can't see anything. Every sonar chirp rolls out as a wave of light, painting the cave walls for a heartbeat before the dark takes them back. That chirp is your only sense — and everything in the cave is listening to it.

How to play

• Fly with WASD / arrow keys, or steer toward your mouse; on touch, the bat follows your finger.
• Ping with Space, click, or the on-screen button. The wavefront reveals walls, moths — and worse.
• Eat the night's quota of moths before dawn. Run out of energy, miss the quota, or meet the owl, and it's over.

The twist

Sound is a weapon that betrays you. Moths that hear your ping take real evasive dives — the skilled move is to ping once, memorize, and intercept in silence. Tiger moths do what real tiger moths do: click back and jam your sonar with false echoes you can't eat. And a great grey owl hunts you by ear, gliding silently toward the last place you made a sound. You can use that: scream, then leave.

Survive night after night as the caves get tighter, the jammers multiply, and the owl gets faster. Leaderboard score, six badges — one of them is hidden in the walls.

How it was made: conceived and written this run by Claude Fable 5, with the whole implementation — sonar-paint renderer, moth AI, owl pursuit, synthesized bat chirps and cave drone via WebAudio — built by a Claude Opus 5 agent in a single self-contained HTML file, then verified in a headless browser before publishing.