An original 3D deep-sea adventure, drawn live with a self-hosted copy of three.js. Sunbeams slant through the shallows and fade as you sink; below a few hundred metres the only light is your headlight, the glow of jellies, corals and ore crystals, and the eyes of things that hunt you. Marine snow drifts past, bubbles stream from the propeller, vents pour scalding plumes and currents sweep through the caves. A Graphics choice (Low, Medium, High) keeps it smooth on modest PCs, and it steps down by itself if the frame rate drops below 30.
Diving: leave the surface dock, explore the cave, grab specimens (24 species of coral, jellies, fish and crabs) and salvage (crates, brass relics, black boxes, sealed pods), and drill glowing ore. Your battery drains every second (lights and sonar cost extra), so get back to the dock to sell. If the battery dies or the hull breaks, a rescue buoy hauls you up, but you lose cargo and pay a tow fee.
Hazards: crushing pressure below your hull's rating, hydrothermal vents, currents and six kinds of predator, from reef barracuda to the Maw Stalker. Lights help you see but let hunters see you too; switch them off to slip past.
Shipyard: upgrade the hull (depth rating 300 m to 10,000 m), battery, lights, sonar, claw and drill (cargo and harder ore), engines and pulse cannon, five levels each.
Leviathans: six bosses guard the bottom of each zone: Reefmaw, the Gloom Lantern, Coilthrasher, the Glass Wyrm, the Trench Colossus and the Drowned Star. Each gets a cinematic intro and has its own lunges, spit volleys, stunning pulses or summoned broods, and grows enraged at half health. Beat one to open the next zone. The full campaign takes several hours. The Daily dive gives everyone the same trench, sub and battery.
Score = a twenty-fifth of all credits earned + 2500 per leviathan + 150 per species catalogued + 60 per upgrade + 15 per predator repelled + 10000 for silencing the Drowned Star, times the difficulty (Explorer 1, Aquanaut 1.25, Abyssal 1.5). Daily score = cargo sold + 150 per species + half your deepest metres + 3000 for the leviathan. Every posted score is replayed on the server.