You build a network of submerged domes and connecting tunnels to sustain human life on the ocean floor. You play cards into specific colored action slots to build farms or desalination plants. Matching the card color to the action slot unlocks powerful bonus combos that accelerate your economy. It is a brilliant engine builder that demands efficient hand management and spatial planning. It plays extremely well even if you only have two players. You will definitely want to play this one again.