Horror that doesn't hold back. Enemies are weird, weapons are original, environment is sadistic.
You will learn about communication problems with the planet-cracker, spaceship Ishimura (a mining ship that destroys planets for ore), the religious movement of the Unitologists, the discovery of the Marker on the planet surface of Aegis 7, and that your name is Isaac Clarke who had volunteered for a reconnaissance mission because of a love interest who is stationed on the ship. There will be documents and conversations as points of discovery to the plot, but much will remain a mystery, only than once boarding the Ishimura, things go immediately wrong and your mission for survival begins. The gameplay does a good job implementing health, energy, ammo loadouts and messages within the confines of your RIG. The third-person perspective will show bars along the RIG's spine as your health meter and a circular readout on one shoulder shows your stasis energy. When aiming with weapons, there will be virtual ammo counters. When receiving transmissions, a 2D hologram will appear before Isaac's face, and while receiving the message you can still look around and move, which makes for a very nice effect to an already great-looking game.
Though the setting is in the future, much of the ship has been trashed among working locations like Stores and Benches. Many items will be scattered throughout corridors and rooms around the ship, sometimes in containers that can be smashed open or within lockers and cabinets. Items will range in various ammo types, credits (to be used at the Store), health packs, stasis modules (to regenerate stasis energy), oxygen canisters and special items like schematics (used to unlock new items in the Store) and power nodes (used to upgrade weapons and RIG components at the Bench). The Store can be used to sell items to save credits that can be used to purchase newer weapons and RIG improvements (like more inventory slots and will absorb more physical damage). Weapon types range from actual weapons to tools (designed for cutting into rock) although you will end up using them to dismember your opponents. Four weapons can be carried at once, while others can be stored in the Store inventory to be used later or sold.
The Plasma Cutter will be the first weapon you learn that will fire a narrow beam of energy (basically a short-burst laser that does a good amount of damage, if upgraded, useful against most Necromorphs). The Line Gun fires a horizontal laser beam that does a good job slicing through a large area to take out multiple opponents at once (an alternate mode will fire mines usually to create a perimeter). The Ripper makes for a good close-quarters weapon that uses a spinning saw blade to annihilate opponents quickly (a secondary fire, and useful, will shoot saw blades at a good distance). The Pulse Rifle has the largest clip and is useful for spraying multiple, weaker Necromorphs at once, and when upgraded to the max still makes a formidable weapon. The Force Gun shoots invisible energy that is useful throwing enemies backwards but not always great for a universal weapon (even when fully upgraded would still take more than several hits to shoot off a limb). The Contact Beam destroys most enemies with one hit but can take time to charge a shot and ammo is scarce and expensive. The Flamethrower is somewhat disappointing, and though can cause a lot of damage, doesn't slow opponents that much, and more importantly can't be used in space and other places deprived of oxygen.
When you find Energy Nodes, you can use them at a Bench to upgrade individual weapon Damage, Ammo capacity, shorten Reload time, increase Speed of fire, and to improve other attributes specific to the weapon. Nodes can also be used to upgrade your RIG for increased hit-points and oxygen capacity, to upgrade Stasis for prolonged times with less energy consumption, and to upgrade Kinesis for grabbing objects from greater distances.
The various types of Necromorph make up the best part of the game as they resemble their human counterpart but have been twisted into something alien.
Slasher - bipedal forms with extra-long limbs used as scythes
Lurker - babies with tentacles that fire a corrosive spray-like ball
Infector - mantis-like that mostly crawls but can fly and reanimates corpses
Brutes - a bunch of corpses mashed together to make one quadruped-like body
Pregnant - crab-like body that can explode full of the swarm
Swarm - very small, blob-like flesh pieces that are relatively weak but leap and stick to do damage
Leaper - scorpion-like in that it crawls and can leap using a long, pointed limb for a tail
Exploder - a bipedal that shrieks and moves with a strange, glowing sac attached to one arm that can cause a devastating explosion
Divider - tall and branch-like made up of smaller creatures, and when taken a certain amount of damage will break apart to attack as the individual creatures, tough to kill quickly
Twitcher - like Slashers but can burst into speed and will have to use stasis to slow them down
Other unique creatures and bosses are Wheezers that simply infect the air quality, Tentacles that attack through holes in the walls and will pull you to your death if you don't act quickly, Guardians that are permanently stuck to a wall usually next to a door and will fire pods to defend itself, the Hunter that will chase you at one point in the game and appears to be invincible, Leviathan (a giant blob with pods), Slug (a giant creature in space), and the Hive Mind (the final boss).
The ambiance of the game creates the feeling that your character is truly alone. Despite arriving with a recon group, you are shortly separated and only have contact with them through video and your character never speaks except for the occasional labored breathing when running and the screams when you get hit. The sounds throughout the ship create the atmosphere that there is always something waiting and moving with you although many times there will be nothing of interest. When in a vacuum, you will hear the muffled stomping of your footfalls or the vibrations of the rifle recoil, but generally you hear almost nothing, creating even more tension when getting attacked. The rooms and hallways are mostly made of metal, and many lined with grates and crawl-spaces that carry echoes and are used as a means for a few types of Necromorphs to travel and burst through to the attack. Some Necromorphs will 'play dead' and then attack as you come within reaching distance. Sometimes knowing what will happen as you play through the game and grow used to the Necromorph tactics, the situations can still be chaotic as you try to create some distance from being overwhelmed.
The physics of zero-gravity can be confusing, often fighting in mid-jump then trying to gain perspective where the enemies are located. Every surface is fair game with the use of magnetized boots to make it so your character doesn't bounce off surfaces when in true vacuum. When in atmospheric pressure, you are unable to jump as the RIG is heavy and running can be slow and tedious. Generally when in a fight, you will have to choose to retreat with some risk-taking as the Necromorphs are much quicker and can easily chase you down. And if they get too close, they will grab at you where you will have to press the 'E' key multiple times as rapidly as possible to throw them off and smash them back with your weapon, all the while as they do damage by rending, biting and stabbing at you. Usually it is best to shoot them from a distance and create a protective perimeter with mines if getting overrun. If you ever get killed, which will probably happen from time to time, you will get to watch a violent scene of Isaac Clarke's body being torn apart or something similar in gory detail. When you shoot limbs off of various Necromorphs, an arm or leg will fly across the room, and if originally upright the creature will fall to the ground and begin crawling towards you, and sometimes other body parts get in the way and begin to pile up. If a certain Necromorph's specialty is to attack with missile fire then it will attack from a distance, sometimes crawling up walls or hanging from rafters upside-down to hit you. If the specialty is close combat, then it will rush you as quickly as possible. In this manner, the AI is very good and makes the gameplay feel even more real.
The look of the Ishimura's interior fits the storyline well in that you will come across advertisements, containers, various furniture, recordings and documents of families and scientists who previously experienced the rise of a Necromorph infection and its wide-spread panic. The dead will be scattered throughout many areas, creating the look of a morgue and a slaughterhouse. The game is intended for horror with a lot of action, and delivers well on both fronts. There are a couple of mini-games that can be played as a diversion (shooting a gun at targets and shooting baskets in a zero-gravity basketball-type game) that will also give out a few power-ups. Otherwise, the game is full of tense moments, whether trying to repair something from the multiple problems when facing a dying ship or fighting off hordes of Necromorphs while hoping that your ammo holds out long enough (especially at higher difficulties). Minor flaws could be pointed in a couple of the weapons like the flamethrower and force gun that they don't help that much compared to the others or a few of the missions might grow redundant in having to repair this or turn on power to that. The game is nevertheless perfect in that it creates a universe that is original and backed by a solid storyline that covers the horrors of science (the discovery of untapped technology), religion (Unitology), the environment (mining planets) and the fears of a small society being wiped out. Dead Space is highly recommended.