Dementium II is somewhat less a survival horror game and more of a first person mystery game with a horror theme.

The game puts the player into control of William Redmoor, a man who had just undergone some kind of brain surgery. We aren't told exactly the kind of procedure that was performed on William, but it is made immediately apparent that he isn't completely sane. Shortly after gaining control over William, the world around the player shifts from the grimy halls of the treatment center to something out of a Freddy Kruger nightmare; rusty iron and chains abound, living corpses are bound on tables with machinery running through them, and hellish creatures appear from out of nowhere to claw you to death. This alternate reality is come to be known as the Plain of Anguish and the player uncontrolably shifts to and from this space during select periods in the game. Usually this space provides the player with a sort of arena of enemies to defeat or allows the player to access an area inaccessible in the real world (in the example of a set of broken stairs preventing the player from getting to the second floor of a building, but transitioning into the Plain of Anguish to find a ledge onto which the player can climb before shifting back and being on the previously inaccessible floor).

As the player progresses they find their way through the treatment center, outside to a snowy Michigan town with all its denizens' bones piled neatly in the center of town, and deep down into an abandoned mine with a large breathing sound echoing its caverns. Interspersed with these locations are trips to the Plain of Anguish, so the player doesn't become bored with any one area. Between exploration, puzzle solving, and battling the hordes of undead; the player is given a nice and balanced experience.

Controls are mapped out like most shooters on the DS, the player moves by using the D-pad and looks around with the touch screen like using a mouse for PC and using the weapon is mapped to the shoulder buttons. An inventory can be brought up via a button on the touch screen where weapons can be switched out and health restored, the item area is limited to a certain number of spaces that can be taken up by both ammo and health items so allocating spots for each can be something of a hassle. There are plenty of spots for everything you need, but that means you have to use guns constantly to ensure that one type of ammo doesn't pile up in your inventory.

The selection of weapons is something of a curiosity. Some weapons function as you think they would; like the shank being a weak melee weapon or the revolver which fires a standard bullet shot. Their are some weapons which are completely over powered; like the shotgun which can hit targets from much farther away than you would think, and the sledgehammer (the weapon I used through most of the game until I found my inventory full up on unused ammo). And then there are completely useless weapons like the flamethrower (copying a page out of the good horror book of Blood by being a spraycan and a lighter) which has little to no range and is only necessary to kill some plant enemies which won't die without it, and the boomerang-like relic which can reach enemies at a distance but does as much damage as the shank on top of being hard to aim and a pain to wait for it to come back.This makes fighting the undead feel a little wonky at times.

The enemies are not intelligent, but that isn't necessary. All they have to do is reach you and kill you; they walk, hop, roll, or fly at you and use whatever attack is programed into their body to make sure you don't survive. All enemies are creepy as heck, like zombies with jaws in their chests or a fat sack that shoots sludge balls at you and giggles as it takes damage. Enemies are generally slow and easy to hit, which is good because they come in packs and it sometimes takes just enough time to kill one before needing to back off in order to avoid another. The only enemy I had a problem with was the little maggot creatures which moaned and came in droves, they were fast and hard to hit; they died in one hit but it was often I who died because they could climb on walls and hit me from behind and I wouldn't see it as soon as I turned around.

Boss encounters were a definite weak spot of the game. One boss proved super annoying as I only had the shank at the time and it walked on the ceiling and barfed down maggots before coming down to give me a chance to kill it, another boss was so easy that I literally stood in the corner of the room and shot the thing while it couldn't touch me. It seemed like the developers wanted to provide the player with an epic horror encounter but fell flat when it came to the execution.

The meat of the game lies in the exploration and atmosphere of the treatment center and its surrounding properties. Scattered papers and notices about the place give clues as to what happened to the place and how it connects to William, all the while the evil doctor from the first game taunts him over the announcement system. Using a flashlight to look around is fun and adds to the creepiness of the game, but doesn't detract from gunplay as William can hold a gun in one hand and the flashlight in the other. The puzzles aren't hard and often follow a Metroid or Castlevania style approach to progression. The player enters an area with a closed off path and a clue as to what is needed to get through, then the player searches the rest of the building until they find a tool, key, or item necessary to opening the closed path. 

The graphics are some of the best on the DS, something a little bit better than a late-era PS1 game but not as good as a PS2 game. The textures are dirty and dull, but the developers use that to their advantage, providing an experience that focuses on hopelessness and loneliness in a creepy place.

Dementium II offers a new player a good 20-30 hour playthrough, a decent amount for this type of game on the DS. Continued playing is offered in the unlockable survival mode which pits the player against waves of enemies, but I feel isn't enough to retain a player who didn't enjoy the main game itself. It is a good title for those who want a good creepy romp,