Sunkenland

Sunkenland imagines a near future where water has swallowed most of the planet. You scavenge a flooded world for what is left of the old one, diving into submerged skyscrapers, nuclear plants and subway tunnels to recover resources, lost technologies and rare pre-apocalypse items. The depths hold danger as well as salvage, so building diving equipment is its own kind of survival.

Your base can sit anywhere: a fortified water stronghold, a repurposed wreck, or a penthouse perched on an island. A modular building system lets you shape it to taste and decorate it with finds from your travels, but it also has to hold against pirate and mutant clans. Walls, barbed wire, traps, surveillance and artillery keep raiders off your territory, while you raid theirs in turn.

Crafting reaches from simple tools and weapons up to a jetski and even a helicopter, provided you have the right workstations and blueprints. Vehicles such as sailboats, jetskis and gyrocopters speed up exploration, while trading runs to friendly atolls swap item for item, since no currency exists. The whole oceanic apocalypse can also be faced cooperatively with friends.