HADAL

Pilot a research submersible from a ship off Guam, down through the twilight zone to the floor of Challenger Deep – almost 11 km below the surface. Free to play in the browser, on desktop and mobile. **The physics is the game.** You sink on steel weights and drop them to rise. Every watt of the battery counts: the cold eats its capacity, the lamp and thrusters drain it, and it has to last the whole way back up. Pressure loads the hull – go deeper than it is rated for and it starts to crack. **Real life of the deep.** 52 real deep-sea species, from lanternfish and viperfish to the Mariana snailfish, each with sources. Light them with your lamp, photograph them and fill your journal. Invented creatures exist too – and they are always labelled as invented. **A research programme.** Discoveries bring grants and reputation. Buy better cameras, bigger batteries and deeper vehicles, open new sites – shelf, slope, hydrothermal vents, mud volcanoes, trench wall – and solve a few real mysteries of the trench. **Calm, not combat.** No enemies and no timers. The tension comes from your decisions and from how far you dare to go. - Keyboard and mouse, touch screens and gamepads - English and Slovak - Your career is saved in the browser; back it up in Settings Made by one developer with an AI coding assistant: the AI wrote the code that draws every pixel and synthesises every sound; no image or audio models were used. Every species and fact is sourced.