As Hydrophobia's title suggests, your greatest foe in this Xbox Live Arcade game is water. This normally life-giving liquid dominates the environments, forcing you to deal with traditional action sequences in surprising new ways. Set in a dystopian near future in which the world is suffering from severe overpopulation, the events in Hydrophobia unfold on The Queen of the World, a huge ship containing the Five Founding Fathers, corporate men who have prospered while others have struggled to sustain themselves during the massive population surge. The ship is attacked by terrorists calling themselves the Malthusians (named after politician Thomas Malthus, who predicted that population growth would outstrip agricultural development). Cue the reluctant hero, systems engineer Kate Wilson, who attempts to uncover the terrorist plot and save the ship's passengers. Wilson is a believable central character, and it is refreshing to see a strong female protagonist.
Throughout Hydrophobia you have to contend with highly realistic flowing water that, while often a source of tension, can be manipulated to solve puzzles or to gain a tactical advantage in combat. Exploding a floating fuel drum can give you a major advantage in a fight, even if the explosion doesn't damage your enemy. The force of the blast can create huge waves that unbalance your foes or send them flying into the environment, knocking them out and drowning them. You can even start oil fires on the surface of the water and then manipulate the waves to push the flames toward hiding enemies. In puzzles, water is generally used to help you traverse an area or reach something that was previously inaccessible. One such scenario has you destroy a section of the ship's already damaged hull to fill a large area with water, allowing Kate to swim up to an area that was previously out of reach.
Unfortunately, in scenarios where Kate needs to swim, the water physics actually work against you and ultimately cause major frustrations. So much effort has gone into the mechanics of the waves that it can often be difficult just to climb out of a pool. The protagonist bounces up and down at the water's edge, as the button prompt to climb out barely stays onscreen long enough for you to respond. Swimming underwater is challenging too, because the controls aren't as responsive as they should be. Hydrophobia also does a poor job of letting you know how long you can last underwater before drowning. The screen only fades in slightly to indicate that Kate has little air left. This problem also permeates the combat, where the same minimal heads-up display fading does little to communicate when you are being hit by enemy fire. This is especially irritating because Kate can only take a handful of hits before being killed, even on the normal difficulty setting.
The combat will feel familiar if you've ever played a cover-based shooter. Kate takes refuge behind obstacles with a press of the A button and can then lean around them to take out enemies. Kate's handgun can be upgraded with different ammo types. You begin with stun rounds that have to be charged by holding down the fire button. The stun is nonlethal unless you hit an enemy many times, so early on in the game, it is important to use the environment against your foes by shooting leaking gas pipes and overhanging electrical cables, for example. Other ammo upgrades are far more effective, though also scarcer. They range from regular bullets to incredibly useful remote-detonated explosives. The rarity of these ammo types heightens the tension as you are constantly under pressure to make sure that your shots are accurate. If you are wasteful with your attacks, you will be reduced to using the stun shot again. Later in the game, this becomes extremely frustrating because charging the weapon makes fighting larger numbers of enemies very difficult. Kate also lacks any sort of melee attack, so in areas where environmental kills aren't possible, you are forced to repeatedly hit enemies with the stun. There is no way to stun enemies and then quickly finish them up close. The enemies themselves lack variety; you spend the whole game fighting the same faceless and nameless terrorists, with little difference in their weapons or attack patterns.
When Kate isn't simply trying to keep her head above water, Hydrophobia has some interesting mechanics that break up the constant threat of a watery grave. There are several enjoyable platforming sections, where Kate must navigate narrow ledges and tough obstacles. There is also a hacking minigame used to unlock hidden areas and security-protected devices. You use the analog sticks to manipulate the frequency and wavelength of a sound to match the electronic signal of the device that Kate is attempting to access. This kind of gameplay is a relaxing break from Kate's otherwise intense fight against the Malthusians.
There are a variety of collectables and unlockable items that entice you to explore the whole of The Queen of the World, enhancing replay value. The most interesting of these are documents and journal entries, which are unlocked as you progress and help to give additional backstory, fleshing out the universe of the game. These really help to convey the story, often more informatively than the cutscenes, which are badly acted and can be difficult to follow. There are also medals to unlock by performing certain actions within a level. Some of these are awarded for completing primary objectives, but others involve accomplishing optional tasks or completing puzzles in unique ways. Upon completing the story, you unlock a Challenge Room where you can take on waves of Malthusian enemies and compete for high scores on the game's leaderboards. All of these extras serve to bulk up the game and give extra weight to what would otherwise been an uninteresting narrative.
Outside of the high-tension underwater action and the impressive physics system, Hydrophobia suffers from mechanics that lack refinement in their execution. The control scheme is counterintuitive, using an unusual button layout, rather than a more traditional third-person action control system. For instance, jumping is mapped to Y, and using your gun sights requires you to draw with the right bumper and aim by clicking the right stick. The game's unnecessarily complex controls are compounded by a HUD that offers little help with navigation around the labyrinth like game world and also by a troublesome checkpoint system that often forces you back several minutes if Kate dies.
Hydrophobia's visuals are impressive, and generate the tense atmosphere that is the best part of the experience. The game is also very challenging; combat and puzzles must be approached with caution because slight mistakes can quickly result in death. Unfortunately, the tension is regularly broken by poor dialogue and voice acting, as well as stereotypical supporting characters. While the physicality of the water creates an impressive and imposing atmosphere, there are too many minor issues that stack up against the overall experience and detract from what could have been a terrific survival horror game.