BLACK SOUND by nhienhoa785

A sea that learned to listen.

You are sealed inside a small survey vessel. There is no direct viewport and no rescue channel. Five stations wait below a silent ocean. Bring back the survey, then decide what else returns with it.

BLACK SOUND is a first-person instrument-driven horror game played inside the Firefox toolbar popup. Its 3D cabin contains a navigation monitor, external camera, condition gauges and emergency service panel. Click an instrument to operate it, or drag the view and interact at the crosshair.

Read the chart, set the helm and control forward or reverse thrust. Rock contact damages the hull. Full thrust raises heat and acoustic contact; sonar pulses and camera flashes also make the vessel easier to find. Quiet running allows the contact to fade.

The external camera renders the same underwater world used by navigation and collision. Approach a numbered station, point the vessel toward it and expose a plate. A short development delay reveals the photograph. Each newly recorded station adds a survey entry and creates a checkpoint.

The five locations include a descent bell, relay field, empty chapel, ossuary and listening well. Mechanical faults develop during the survey. The service panel restores the hull, generator and optics using reusable tools, with a cooldown between repairs. An optional unregistered signal can be recovered away from the main route.

After all five records, return to the descent marker and choose whether to keep the archive sealed or transmit it. Both choices have a complete ending. A station checkpoint remains available for recovery or replay.

Features:
- A complete game inside the Firefox toolbar popup.
- A 3D cabin with interactive instruments and procedural materials.
- A navigable trench with seven rock formations and five survey stations.
- Shared coordinates for navigation, obstacles and external camera imagery.
- Hull, power, optics, heat and acoustic-contact systems.
- Reusable emergency maintenance and station checkpoints.
- An optional recording and two ending choices.
- Synthesized local audio with a volume control.
- Adjustable look sensitivity, reduced rendering resolution and motion control.
- Local saves with previous-save recovery.

The game pauses when closed. It does not continue moving the vessel or damaging the hull while the popup is absent. No account, ads, purchases, analytics or network connection are used.