The next major update in No Man’s Sky is focused on underwater life. Developer Hello Games detailed the exploration game’s newest expansion, called “The Abyss,” which is launching today on all platforms. “The Abyss” appears to add significantly to what players can expect from the game’s already vast but sometimes empty alien oceans, and it also continues to flesh out No Man’s Sky’s growing horror elements.

The biggest change is the sheer amount of variety that’s being added to aquatic biomes. “Underwater creatures have become more frequent, and more interesting,” Hello explains. “Aquatic life inhabits the full depth of the ocean, and unique terrifying creatures can be encountered on the ocean floor.” There will be new sunken wrecks to discover and a submarine, called the Nautilon, that you can build for safer underwater exploration. Hello is also adding more options for building underwater bases, including a range of glass corridors so you can get an uninterrupted view of the depths.

The game is also getting a new storyline called “The Dreams of the Deep,” which Hello says “brings a new context to the depths and a dark narrative to No Man’s Sky.” It’s no accident that the expansion is launching so close to Halloween: among the new creatures are a number of horrifying sea monsters, including what looks like a massive angler fish and a giant yellow eye that lives on the seafloor.

Though it launched back in 2016, No Man’s Sky has seen a resurgence this year, thanks to the massive “Next” expansion, which added more variety to the worlds you explore, vastly improved visuals, a completely revamped storyline, and the long-awaited inclusion of multiplayer. As with all previous updates, “The Abyss” will be available for free to all players when it launches today.