This review will consist of two parts: firstly a detailed overview of the game in order to provide information and context, and secondly my personal opinions and ratings. I believe that including a detailed overview is important; a comprehensive description will probably influence someone's perspective even more than me just saying what I do and don't like about the game.

Part 1: Overview
Depth is an asymmetrical online multiplayer game on the Steam platform in which two teams compete directly against each other: a team of four divers playing a first-person shooter, and a team of two sharks playing a third-person brawler.

Divers
      The objective of the divers is to escort S.T.E.V.E., a custom-built aquatic robot, through one of several underwater maps as S.T.E.V.E. bypasses the locks on various safes and treasure chests. Furthermore, there is loose treasure scattered throughout the map, which divers can collect and "cash in" by giving it to S.T.E.V.E. Each time a diver cashes in an item, the entire team earns $50 each, and each time S.T.E.V.E. opens a safe, the entire team earns $1000 each.
      Whenever a diver dies, they can spend their cash on new gear that they will respawn with. Gear consists of three general categories: weapons, tools, and consumables. Weapons include bang sticks, net guns, spear guns, harpoons, and underwater firearms such as the SPP-1, P11, APS, and ADS. Tools consist of a sensor, which has a metal detector for finding treasure as well as sonar for locating sharks; and a diver propulsion vehicle (DPV) that enables divers to move rapidly across the map for the purpose of gathering treasure or evading sharks. Finally, consumables include underwater flares, sonar buoys, explosive mines, first-aid kits, shark shields, and a portable aquatic turret that automatically tracks and shoots at sharks that enter its field of view. Additionally, most weapons and tools can be upgraded: pistols can be dual-wielded, rifles can have extra mags and scopes, ammunition can have toxic, tranquilizing, tagging, or bleeding effects, harpoons can be fitted with explosive tips, nets can be reinforced and barbed, the DPV can be turbo-charged and equipped with a metal detector, and so on and so forth. Furthermore, each diver has a diving knife that they can use to stab sharks while being thrashed, as well as a hyperbaric welding torch that can be used to repair S.T.E.V.E.
      Whenever a diver is bleeding, severely wounded, or out of ammo, they should seek out a first aid kit or an ammo box. These are spread throughout the map (usually in remote locations that aren't close to S.T.E.V.E.). Divers can also use portable first aid kits that were purchased and deployed by themselves or a teammate.
      Each team has certain advantages and disadvantages; the divers' advantages are their access to a wide variety of gear that can kill or deter sharks from a distance, and the size of their team. Since the diving team has twice as many players as the shark team, teamwork and cooperation can give skilled divers a huge advantage. Using the buddy system and watching each others' backs are important. The divers' disadvantages, however, stem from the fact that the divers are not in their native environment. Visibility is limited in the dark, murky depths, and swimming with heavy gear is slow and awkward. The first-person perspective of the divers also reduces perception, compared to the sharks' third-person perspective. A diver's only indication that a hidden shark is nearby is through a game mechanic whereby your heart beats harder and faster when you are closer to a shark.
      The diving team wins when one of two conditions are fulfilled: either S.T.E.V.E. opens all safes and safely returns to the extraction point, or the shark team loses all of its lives.

Sharks
      The objective of the sharks is to kill all divers. Killing a diver is accomplished by darting or lunging into a diver to grab them, and shaking your mouse rapidly to thrash them. Whenever a shark kills a diver, that shark earns 10 evolution points.
      When a shark dies, that shark may spend its evolution points on evolutions (i.e., perks) before respawning. A few examples of evolutions are: enhanced ampullae of Lorenzini to see more detailed information about divers' health and equipment; razor-sharp fins; serrated teeth so that divers continue to bleed after breaking free from your jaws; and various evolutions that increase speed, stamina, health regeneration, or maneuverability. In addition to evolutions (which are passive abilities), each shark has an active ability that can be upgraded with evolution points. The active ability is activated by pressing "E" and will give the shark some sort of temporary boost, after which a cool-down period is required before the ability can be activated again. The active ability is determined by the shark's species. You select your shark's species at the beginning of the match and it cannot be changed during the match. The species are as follows: Great White, Mako, Tiger, Hammerhead, Thresher, and Bull.
      The Great White was the first playable shark in the game when Depth was first released. Its defining attributes are durability and damage output. It is an extremely large, tank-like shark that relies on brute force, and it lacks the speed, stamina, and maneuverability to employ stealthy hit-and-run tactics. Its active ability is called Juggernaut, and once activated, the Great White temporarily gains a high resistance to damage. The Great White is by default the most durable shark in the game, and once Juggernaut is fully upgraded and active, the Great White can even withstand direct facial contact with an explosive mine.
      Next is the Mako. The Mako's defining attributes are speed, maneuverability, and damage output. It is small, lightning-fast, and can thrash a diver to death very quickly. On the other hand, it has extremely low durability. Being a glass cannon, so to speak, the Mako ought to rely on hit-and-run tactics, catching divers alone or carrying divers away from the group. If a Mako engages a group of divers clustered together and watching each others' backs, it will die very quickly, usually before it has a chance to earn a single kill. The Mako's active ability is Mark Prey. When activated, the diver that the Mako is currently facing temporarily becomes "marked." Whenever a diver that is marked dies, the Mako earns additional evolution points. This enables the Mako to afford more expensive and powerful evolutions.
      The Tiger's best qualities are being well-rounded and stealthy. The Tiger is medium-sized, more durable than the Mako and more maneuverable than the Great White, and its damage output is just as high as both of theirs. It is a jack-of-all-trades that can employ either hit-and-run or all-out aggression tactics, does well on all maps, pairs well with all other sharks, and it has a lower skill ceiling, making it an excellent choice for beginners. However, because it lacks specialization, expert players tend to use the Tiger less often as they realize the potential of other species. The Tiger's active ability is Adaptive Hide. While active, the Tiger's camouflage enables it to evade detection by flares and sonar.
      The Hammerhead is a large shark similar to the Great White. It is slightly faster and more maneuverable, and slightly less durable than the Great White. It also deals much less damage than the three aforementioned sharks when thrashing prey. However, it deals incredible damage when it swims into solid objects with prey in its mouth. It literally uses its head as a hammer to smash prey into a pulp. The Hammerhead does well on maps that feature close-quarters combat, narrow corridors, a lot of walls, etc. On the other hand, the Hammerhead is weak on maps where there is a lot of open water. The Hammerhead's active ability is Relentless Force. While active, the Hammerhead regains stamina and health whenever it impacts a solid object. This can give the Hammerhead an opportunity to either escape or grab another diver after smashing one diver into a wall.
      The Thresher's defining qualities are its speed and propensity for teamwork. It is arguably the most difficult shark to hit. It has the speed, stamina, and small size of the Mako. In addition, while thrashing prey, it moves around wildly, making it a difficult target. It is unique in that it is the only shark that deals area-of-effect damage. Its thrashing damage is low, but while it is thrashing, its blade-like tail wounds and disorients any divers caught in the area of effect. This can "soften up" the entire diving team for the Thresher's teammate to finish them off; alternately, the Thresher can kill multiple divers at once. The Thresher's weakness, like the Mako, is its lack of durability. The Thresher's active ability is Tail Lash. When activated, it creates a pressure differential that immediately damages nearby divers, disables their flashlights (temporarily), and can potentially destroy their consumables and break walls.
      Last but not least is the Bull. The Bull is a medium-sized shark with well-rounded attributes, similar to the Tiger. The Bull is defined by its active ability more so than any other shark. When the Bull is near one or more divers, it gradually gains something called "rage." The rate at which rage is gained increases when the divers are more active; if the divers swim around, use consumables, fire their weapons, etc. then the Bull will gain rage very quickly. When the Bull activates its ability, Enrage, it temporarily gains bonuses to its health, stamina, and damage output. The bonuses are proportional to the amount of rage that the Bull has. This ability makes the Bull well-suited to teamwork, like the Thresher. Whereas the Thresher can weaken an entire team to allow its teammate to destroy them, the Bull can hang back and build rage while the divers shoot at its teammate, and then rush in while fully enraged.
      Whenever a shark becomes hurt, it can heal by hunting seals that swim around the map near the surface. Eating two or three seals will restore most critically wounded sharks to full health.
      Like the diving team, the shark team has certain advantages and disadvantages. Its advantages are speed and perception. Sharks can cover large distances in a short amount of time. Sharks can tell exactly where S.T.E.V.E. is at any given point in time, and the sharks also have a pseudo-sonar that periodically shows the location of divers, even from across the map. For shark players, the screen is well-lit and the third-person perspective gives them a wide field of view. In short, the sharks have the advantage of fighting in their native environment. The sharks' disadvantage is their weakness against ranged weaponry. Sharks must get up close and personal with their prey, which makes them vulnerable to the divers' weapons and other technology.
      The shark team wins only when the diving team loses all of its lives. There is, however, an alternate way of doing this aside from killing the divers over and over again: if the sharks completely destroy S.T.E.V.E., then the boat captain who financed the treasure hunt will become angry and abandon the divers. This means that divers can't respawn and are now on their last life.

Depth has a small, but active player base and has five servers around the world. Its development team supports the game well and releases major updates every few months with minor "hotfixes" as needed in order to eliminate bugs, glitches, and game balance problems. Each major update introduces new maps, skins, diver equipment, shark species, and/or gameplay features, so the content of the game stays fresh. The downside of having a small player base, however, is that matchmaking is unbalanced. It is quite common to see a team of level 75+ expert players face off against a team of new players that are all below level 30.

Part 2: Ratings

Graphics: 9/10
In terms of graphics, Depth isn't an ultra top-notch state-of-the-art high-end game. Truth be told, that's how I like it; if a game requires expensive hardware to run smoothly, then I'm not interested. That being said, Depth is actually very beautiful. The developers paid a lot of attention to detail when constructing the scenery. Also, the graphical contrast between playing as a shark and playing as a diver is brilliantly implemented. As a diver, the water is murky and dark and there are a lot of blues that create a survival-horror atmosphere. The mood created by the game's visuals constantly reminds you that you are prey. On the other hand, when playing as a shark, the world is clear and brightly lit, with high contrast and accented reds. The visuals make you actually feel like your senses are sharper, and it perfectly suits gameplay as an apex predator.

Sound: 10/10
Hooo boy. The sounds in this game are amazing, especially for divers. In a world where you can barely see, you rely heavily on sound to keep track of your surroundings. The tense ambient music, the swish of a 2,000-pound predator swimming nearby, the screams of your teammates being devoured, and the pounding of your character's terrified heartbeat help to create exactly the kind of atmosphere that this game needs.

Addictiveness: 10/10
I don't know what to say. I can't stop playing. I'm usually more into story-driven games, but there's something about the visceral thrill of Depth that keeps me coming back. It's one of the most creative and well-executed action games I've ever played.

Story: 7/10
Depth isn't a story-driven game by any means, and there isn't a lot of consistency in the lore. The divers work for Captain Stubbs, a greedy treasure hunter who lost an arm in a shark attack. Players can choose from five different divers, who each have their own backstory, although some of their backstories don't quite make sense in the context of treasure hunting. The divers illegally pilfer sunken ruins, such as ancient Aztec burial grounds, Medieval castles, shipwrecks, oil derricks, and more. The sharks serve as brutal forces of nature, guarding their habitat from the intruders. In this sort of game, story really doesn't matter, but I applaud the developers for at least including tidbits of lore and backstory.

Depth (lol): 6/10
There is only one viable game mode (Blood and Gold, which I have been describing in this review so far). There are a couple of alternate game modes, such as Hide-and-Seek and Megalodon Hunt, but it is nearly impossible to find a match with them because hardly anyone plays them. I will admit that once you've played all of the maps, playing the same game mode over and over again starts to get repetitive. I personally rely on updates and positive interactions with other players to keep the experience fresh.

Difficulty: 7/10
Depth has a very high skill ceiling and a steep learning curve, making the game difficult for new players. I recommend playing with a friend if you can, and playing private matches against bots to hone your skills.

Overall: 8.4/10