Depth is a team based multiplayer action game taking place under the sea where players can take control of either sharks or human divers. The original game mode is Blood and Gold and in it a team of four divers have to escort a robot called S.T.E.V.E. as he opens up treasure safes. Once all safes have been opened the team returns to their boat and they win the game. The other team consists of two sharks and these have to stop the divers from getting away alive. They can also win the game by attacking and destroying S.T.E.V.E. Divers equipped with a welder can repair their robot companion. A game also ends when one team has lost all team tickets. Both divers and sharks have a set number of tickets and these will be decreased every time someone is killed.
Divers see the game through a first person perspective and has when starting access to a knife (which can be changed to a welder) as well as a small amount of cash to buy a gun or consumables. As safes are opened they earn more money that can be used to acquire better weapons, upgrades and other equipment. A diver can carry two guns at a time and there are several to choose from including pistols, rifles and spear guns. If caught by a shark a diver's only chance is to repeatedly stab it with the knife/welder or hope that a team mate shoots it. Extra money can be earned by collecting loose treasure. Since the sea is dark and sharks are hard to spot various gadgets such as flares, sonar buoys and tagging bullets can be used. It is however possible to hear when sharks are near as the diver's heart will beat heavily.
Sharks play the game from a third person perspective and instead of weapons they can acquire evolutions with the points that they earn from killing divers. There are different sharks to choose from (great white, hammerhead, mako etc.) and each has different values in durability, speed, agility and thrash damage. The darkness of the sea is less of an issue for the sharks since their sonar allow them to see divers from afar. Sharks are also fast and can lunge through the water to quickly catch divers. Once a diver is caught the shark can kill it off by doing rapid movements with the mouse to thrash the prey. Sharks also have the ability to break through certain structures to surprise the divers.
Two additional game modes have been added through updates: Megalodon Hunt and Hide and Seek. In Megalodon Hunt all players start as divers and have to kill the Medalodon. The one player that succeeds with this becomes the Megalodon and can go after the other players. Divers can't buy any weapons in this mode but can upgrade their weapons by collecting treasure. The first player to reach 10,000 points wins the game. In Hide and Seek one player starts as shark and has to hunt the divers. Divers that are killed will join the sharks and when all divers have died, the sharks will win.