EchoDepths: Sonar Roguelite

A kilometer below the surface, light has never existed.

You are a blind cave salamander in a flooded labyrinth. The screen is black. Tap, and a ring of sound blooms outward, painting the cavern walls in fading phosphor lines — the ledge above you, the tunnel splitting left, the smooth swell of something large and alive that just turned toward the noise.

EchoDepths is a one-thumb roguelite where sound is both your only sense and your greatest liability. Every ping buys you vision and sells your position. The whole game lives inside that trade.

SEE WITH SOUND
• Tap to click: three meters of wall, faintly, for two seconds. Cheap and quiet.
• Hold to chirp: eight meters, clearly — the map you need, and the sound that wakes a bristlemaw two tunnels over.
• Hold longer to shout: the whole chamber for six seconds. It echoes. Everything hears it.
• Walls fade from phosphor to ember to black. Skilled players ping once and swim through what they remember.

SURVIVE BY LISTENING
• Bristlemaws drift toward the last sound. Anglers hold still and lash at anything that pings nearby. The Warden bellows — and gets faster every time you shout.
• Predators make their own sounds, panned and attenuated by where they really are, so you can track them without pinging at all.
• There is no attack. Route around them, glide silently, throw a pebble somewhere else.

EVOLVE YOUR SENSES
• Descend through Rootwater Shallows, the Chimney Forest, the Still Black and the Warden's Throat — procedurally assembled, different every dive.
• Death is permanent for the run. Keep your otoliths and spend them in the Grotto on senses, not stats: a lateral line that feels movement, heat pits that see warmth, a vocal sac that turns your tap into a whisper.
• Long-press an evolution to feel its haptic preview before you buy it.

PLAY EYES CLOSED
• Eyes Closed mode hides every visual. Spatial audio and a designed haptic vocabulary carry the entire game, and predator bearings are spoken through your screen reader.
• Menus are real, TalkBack-navigable buttons. Nothing on screen ever flashes.
• An assist mode (Abyssal Calm) slows predators and lengthens the fade for anyone who wants the atmosphere without the pressure.

THE PLEDGE
• No ads. No energy timers. No accounts. The app does not even request internet permission.
• Fully offline. Your save lives on your phone.
• Daily Descent: one cave, one attempt, the same seed for everyone today.

This is the v0.1 vertical slice. The global daily leaderboard and the Full Depths unlock arrive with v1.0.

Headphones recommended. Haptics on.

Recent changes:
A new face for the dark. The title screen is now a live sonar scene: a lamp hangs in a real cave, and every few seconds a ring of sound leaves it and lights the walls as it reaches them. Cyan on deep navy is the new default; your saved palette is kept.

The cave stays silent behind the pause menu. The death screen shows the sonar art of your run clearly. The grotto has its cave drawn in. New sliders, icons and launcher icon.

Nothing leaves your phone. Your save carries over.