Cosmic Ocean is displayed as an extension of Area 7 in-game, with the first level of the area labeled as 7-5. There are 94 levels that the player must beat to reach the 3rd and final ending of the game, culminating in 7-99, where a Constellation is created. 7-98 is the final level of gameplay; 7-99 is where the Special Ending takes place and is displayed as the final level in the Run Recap screen.
Although Cosmic Ocean is displayed everywhere as part of Area 7, internally, it is considered Area 8. This means that Treasure becomes even more valuable compared to Sunken City, with treasure in Cosmic Ocean being worth +175% / 2.75x what it is initially worth in Dwelling.
Cosmic Ocean is an assorted blend of previous areas, with each level being themed to a respective one:
All areas contain their respective enemies and traps, with the following exceptions:
- Bear Traps in Jungle and Tide Pool
- Giant Spiders in Jungle
- Lavamanders in Volcana
- Goliath Frogs in Sunken City
Cosmic Ocean levels do not have unbreakable borders and instead have an empty space in its place. This empty space loops around within itself both vertically and horizontally. This effectively makes it so that if a player, item, or any other entity or object falls down far enough in a level of Cosmic Ocean, they will end up at the top, and going too far towards the left or right side of the stage will leave them in the opposite end. Each level is always of varying width and height. Levels can range from 3-6 rooms wide and 2-6 rooms tall, resulting the smallest level being 3x2 rooms big and the largest level being 6x6 rooms big.
In every level a Celestial Jelly blocks the exit door, instantly killing any Spelunker that gets too close. To bring the Celestial Jelly out of its dormant state and move it away from the exit door, three Floating Orbs scattered randomly throughout the level must be destroyed. Once the third Floating Orb is destroyed, the Celestial Jelly will chase the Spelunker, still instantly killing on contact.
Staying in a level for over 3 minutes spawns a second, active Celestial Jelly in place of the Ghost.
Pets, Curse Pots, Shops, Vaults, and Kali Altars do not spawn in Cosmic Ocean levels. No Kali Altars or Pets makes the only sources of healing either a Kapala obtained prior to entering, or cooking turkeys randomly found in ice. If the Spelunker is Poisoned or Cursed, the only ways to remove the affliction are to either use Elixir's buff or to die and resurrect with the Ankh (retained through various means). On the other hand, neither angry Shopkeepers nor will an angered Tun appear in Cosmic Ocean levels.
Cosmic Ocean level generation is different from standard level generation, and as such the player may be in danger the moment they enter a level, such as a Giant Crush Trap appearing just above the entrance of a Temple of Anubis themed level or an Elevator appearing above the entrance of a Neo Babylon themed level.
Rope can still be thrown and placed in Cosmic Ocean normally, despite them not having a wall to cling to. This also applies to Grub and other entities that cling to walls.
In multiplayer, player coffins will only spawn on levels 7-10, 7-50, and 7-90.
Entering Cosmic Ocean awards the following Feat:
|Spelunky 2 Places|
|Area 2 A||Jungle (Black Market)|
|Area 2 B||Volcana (Vlad's Castle)|
|Area 3||Olmec's Lair|
|Area 4 A||Tide Pool • Abzu|
|Area 4 B||Temple of Anubis • The City of Gold • Duat|
|Area 5||Ice Caves|
|Area 6||Neo Babylon • Tiamat's Throne|
|Area 7||Sunken City • Eggplant World • Hundun's Hideaway|
|Area 8||Cosmic Ocean|
|See also||Level Feelings|