As I read through the back story for Hydrophobia: Prophecy, a new release from Dark Energy Digital, Ltd., I couldn’t help thinking that the premise could provide bountiful fodder for those inclined to look for allegories applicable to the contemporaneous political and sociological rifts we deal with today.  The story is set in the mid 21st century at roughly the period when the effects of the profligate and mostly unfettered excesses of the late 20th to early 21st centuries have brought about a “Malthusian catastrophe.”  I’ll save you a trip to Wikipedia: A Malthusian catastrophe is a forced return to subsistence-level conditions once population growth has outpaced agricultural production, energy production, or any of the other vital needs for preserving humanity.  
Not surprisingly for a game called ‘Hydrophobia’, water plays a central role in the story; the Malthusian catastrophe that is the basis of the game is a global lack of fresh water.  The resulting famine and poverty have caused an irreparable radicalization of the diametrically opposed capitalists and environmentalists, the latter being cast as ‘Neo-Malthusians.’  The capitalists have retreated to a massive ship-borne city where they research nano-technology means for converting oceanic salt water to fresh water.  The Neo-Malthusians are having none of that; they believe the problem can be more readily solved by exterminating most of the world’s population. As with the radical moonbats that suggest the same type of solution today, they themselves are fundamentally lacking in the desire to lead by example. Their alternative is to attack and hijack the capitalists’ floating city, presumably having failed in having the government co-opt it through burdensome legislative regulations or extra-judicial maneuvering.

 
This is, of course, where you come in.  You play the part of Kate Wilson, a systems engineer who will be tasked with saving the ship from the bad guys. Her job will be complicated by the fact that the attack by the Neo-Malthusians as caused quite a bit of damage to the ship. In fact, the lower decks are awash with sea water and rife with ruptured gas pipes that are prone to bursts of extremely dangerous fire.  As is common in single protagonist action games, Kate also is in nearly constant contact with an expository voice to explain what’s going on and to periodically provide advice and clever quips.  She also has a handheld device that appears to be a distant descendant of today’s iPad.  It has some interesting apps that she can use to hack into various systems on the ship or get through encrypted door locks.
On the technology front, Hydrophobia uses Dark Energy’s proprietary HydroEngine technology to manage the detailed and highly accurate flow of the thousands of gallons of water that threaten to sink the ship and/or drown Kate.  Designed by an astrophysicist with a specialization in nebula formation (I’m not making that up!), the intricate mathematics and complex rendering solved the problems that arise when using water as a central point of the game, but also introduced further complexities. For example, the AI need to have an autonomous design that allows each of them to respond to the varying  conditions created by player decisions that vary the level and behavior of water in a given strategic situation.  Other objects in the game, such as the ubiquitous crates and barrels than populate the hallways and storage holds, also need to behave realistically in the water.
Dark Energy’s web site describes the technology:
“The HydroEngine simulation shows all the subtle physical effects that are essential for maintaining the suspension of disbelief - water flowing around complex geometry creates eddies in backwaters, waves interact in a highly nonlinear way and we see all the chaotic behaviour we expect in real fluids. The flow interacts with all the physics objects in the world, and imparts flow and buoyancy forces which carry objects along, showing subtle effects such as the rotation imparted to objects moving in a shear flow.”The part about “interacting with objects in the world” is achieved  through the marriage of the HydroEngine with the venerable Havok physics  engine. What this means to  the player is that the wave action of the  water is enhanced by physical objects in the game being washed around in  a very realistic way.  Because of the inherent randomness of flowing  water as modeled by the HydroEngine and the realistic response of  objects, the player is immersed (so to speak) in an extremely believable  environment.  Many of the effects have a direct bearing on the game as  well. Kate is able to move through shallow water rather easily, but when  the serious flooding starts it can be a challenge to simply get her to  where she needs to go. The wave action of the water also causes problems  in cases where you are trying to Kate to draw a bead on a target, only  to have an inconvenient wave come along and disrupt her aim. There are  also a number of times when the electrical conductivity of salt water  can have a deleterious effect on Kate’s health.  One is well advised to  pay attention to dangling electrical wires and the resulting sparks near  the water and to not allow the flow of the water to move poor old Kate  into a danger zone.  I personally have negligently allowed poor old Kate  to meet her demise in the most shocking ways numerous times.
There are also times when Kate is forced to swim long-ish distances  through completely flooded areas where there is no opportunity to  surface and take a breath. Kate’s lung-reserve is graphically displayed  on the screen to help the player know when the situation is getting  desperate. As the pressure builds, Kate’s pulse rate increases. Combined  with the flow of the water and the feeling of impending drowning, the  feeling of being under water and swimming for your life becomes very  visceral.  Before you know it, you too are holding your breath as you  hunt for the next pocket of air.

 
The game play itself is rather rudimentary run-and-gun, although there  is a cover capability offered. Playing on the normal level, I never felt  much need for it and I wasn’t particularly good at it anyway.  I  struggled with getting around corners without accidentally exposing  poor, poor Kate to enemy fire. Lucky for Kate, the AI is not overly  brilliant and it was usually easy enough to just hide behind a  convenient object or duck under water for as long as it took for the AI  to do something stupid. It did come as an unpleasant surprise to learn  that the AI can not only also swim underwater, but can fire their  weapons under water as well.  Poor old Kate, again.  
Kate’s primary weapon is a sonic gun that has the benefit of never  running dry (so to speak) of ammo, but comes at the cost of what can  seem an interminably long recharge time. Of the various other innovative  weapons to be found, my favorite by far was the gel rounds. These can  be more or less silently fired into/onto a malevolent bad guy, then  detonated remotely. Sneaky!

 
When it comes to moving around on the ship, there is a puzzle aspect to  the game wherein Kate often needs to figure out how to navigate her way  around damaged decks or open flame. This more often than not involves  climbing, although there are many cases where the judicious opening of  doors will release a flood of water that will wash out flames or sweep  away bad guys. Strangely, given the very tight restrictions regarding  the handling of explosive or flammable objects on ships, there are also  quite a few objects floating around that can be blown up in order to  exterminate some pesky AI opponents.  Or just for fun, for that matter.
The path Kate takes on her journeys through the ship is very linear, but  not always obvious. Many of the doors and decks look the same, just as  one would expect on a ship, so it is easy to get lost.  There are two  solutions for this available to the player.  First, the player can  select HUD mode. In this mode, waypoint markers lead the way through the  path. Alternatively, if that mode is too easy (and, frankly, it is) the  player can select MAVI mode.  The MAVI is the aforementioned iPad-ish  device that provides the interface to the ship’s systems. In MAVI mode,  the device shows navigational arrows that give a general sense of the  proper direction painted on the walls of the ship.In either game play mode, the MAVI is also used to find encryption codes  painted on the walls. These are used to open locked doors.  I didn’t  fully understand how encryption codes came to be painted on the walls in  the first place; that could be part of the back story that I just  didn’t catch. Other doors and consoles required a much cooler decryption  process in which the MAVI is used in conjunction with the mouse (PC  version) to match the amplitude and frequency of a sine wave. Those were  much more fun.  Actually, I rate it as one of the coolest ‘unlock’  mechanisms I’ve ever seen.
While the path through the game is linear, there are small branches in  the story itself. For example, if Kate is tasked with saving the life of  an innocent crewman in danger of being executed by one of the  terrorists, the story will respond differently if she succeeds or if she  doesn’t. I much prefer that approach to the alternative style of  failing back to the previous checkpoint in the case of a failure to  achieve the goal.

 
Hydrophobia uses a third-person perspective which I am normally not a  big fan of. The usual underlying reasons for my dislike of the  third-person were apparent in Hydrophobia as well. I nearly always find  the control of the camera to be difficult and restrictive, and such was  definitely the case here, under certain conditions. There were times  when I wanted to be able to look up to get an eye on AI opponents that I  could hear tromping on a catwalk above me or to look for pipes that I  could climb on in order to get to a higher deck level, but my range of  camera motion often wouldn’t allow it. I also had trouble with the  camera while Kate was swimming underwater. If she was deep enough under  the surface, it worked okay. It was when she was skimming just below the  surface that I seemed to struggle with keeping the camera either under  or above the water.
While their are some interesting innovations, the game play is pretty  standard. What sets Hydrophobia apart from the rest of the pack is the  way that the water influences player strategy. While you could run  through a room shooting the bad guys one by one, or you could wait for  them to congregate near an explosive barrel,  it’s much more gratifying  to find a way to get the water to do the job for you.   Eventually,  though, the novelty of the impressive use of water begins to wear off  and the game becomes somewhat repetitive. While it never becomes overtly  boring, there will be times when you feel like you’ve hacked into quite  enough consoles and flooded or drained your limit of cargo holds, thank  you very much.

 
This is, of course, the fundamental design challenge of limiting the  game to the interior spaces and lower decks of a ship. There simply  isn’t that much variety to be had. With that said, there were still a  few novel solutions to puzzles to be found in the later stages of the  game. In one example, the buoyancy of cargo drums played a major role in  escaping from a flooded cargo hold. In another example, grabbing hold  of floating detritus and using it as cover while swimming was something I  don’t think I’ve done before.  It’s that type of interaction with the  realistically behaving properties of the water that makes Hydrophobia:  Prophecy something new and unique in a crowded market and, it should be  said, well worth the very reasonable $12 price.