The game launched in early access on September 26, 2019.
The Steam page says:
Survive, navigate the endless garbage sea, and rescue survivors in this spectacular floating city building simulator. Command drifters, explore flooded ruins, visit rusty factories, and learn the stories of the old world.
Players will turn ocean garbage into homes, workshops and gardens, desalinate water, catch fish and strengthen shelters. Exploration of the flooded world, rescuing survivors and animals, a number of technologies and city development are promised. Each drifter has their own story, and specialists will discover new buildings, tasks and opportunities.