Subnautica is a open world underwater survival game on pc, xbox, and playstation. Subnautica is a very fun (but buggy) game. Subnautica allows the player to roam a alien water planet called planet 4546B. Facing all different unique characters and bosses while collecting resources to survive. Subnautica was first released in 2014 in early access for microsoft windows. Subnautica has a few different modes for players to choose from, Survival, Freedom Mode, Hardcore Mode, and Creative Mode. Survival is a mode where you have to find food, water, and resources to survive all while you try not to drown by keeping a balanced O2 level. Freedom mode is just live survival mode except you don't have to worry about O2, food, and water. Hardcore is like survival except you can't respawn when you die, you just die and the file will auto delete. And creative mode is where you can't die and you get unlimited resources, food, water, and O2, and you can craft anything without having to collect the resources for it. Subnautica takes place in the late 22nd century, when humanity begins to colonize planets in space. A vessel constructed by the trans-gov Alterra, known as the "Aurora", has been sent to the outer reaches of controlled space on its maiden voyage with the goal of constructing a form of high speed space travel structure known as a Phase Gate. The Aurora was chosen for this mission due to its new, advanced scanners, and to find a lost ship, called the Degasi, which crashed on planet 4546B long ago. While the Aurora was cruising around the planet, it was hit by an unknown energy pulse, resulting in catastrophic hull failure, which then crash landed on 4546B. Several lifepods are jettisoned from the Aurora as it was crashing, one containing the player. The other lifepods' inhabitants perish through various means, leaving the player as the only survivor. The player finds records of the Degasi crew but two are confirmed dead and one is presumed dead. The player also learns of the existence of the "Precursors", an alien race that came to this planet to research a bacteria called the "Kharaa". 4546B is under automated quarantine due to the bacteria escaping in an accident. The Quarantine Enforcement Platform shoots down ships that attempt to leave, land or enter orbit in order to stop the bacterium from spreading to other worlds. The player witnesses this happen when another ship, the Sunbeam, detects the Aurora's distress signal. The Sunbeam tries to land to attempt a rescue but is shot down. When the player attempts to deactivate the installation it fails due to the player being "infected". In order to leave the planet, the player must find the Precursors' base deep underground to find the Sea Emperor Leviathan. It has been keeping the life in the area alive by using small creatures known as "Peepers" to distribute small amounts of a degraded form of the cure. This keeps the flora and fauna from dying but it is insufficient and not of high enough quality to eradicate it from the ecosystem. It asks the player to help it hatch its eggs because the young produce the cure, known as "Enzyme 42", in a purer form. Once the player hatches the eggs using a hatching enzyme received from the Sea Emperor Leviathan, a sufficient form Enzyme 42 is released from the babies. The player is then cured of the infection and are free to disable the Quarantine Enforcement Platform and construct a rocket to leave the planet, ending the game. The game officially supports VR headsets such as the HTC Vive and the Oculus Rift with the additional input of a keyboard and mouse or game controller according to the Steam sale page of the game. The development team opted to use the Unity engine rather than Spark, the engine used for the company's previous game, Natural Selection 2. Subnautica producer Hugh Jeremy justified this decision because of the different demands that the game places on the engine, and "because [the team] does not include people working on Spark, it's not appropriate for Subnautica to use Spark. By using Unity for Subnautica, Spark can continue to develop in certain directions, while Subnautica develops in others. To use Spark for Subnautica would be like trying to fit a square peg in a round hole."