A totally immersive and terrifying game.
The gameplay in Dead Space is similar to Resident Evil 4 meets Gears of War. There is no cover system, but you use a two-stick control scheme to strafe and look/aim. The weapon sight is brought up with a shoulder button, and fired with the other shoulder button while up. Isaac can also use melee attacks, he is able to swing his weapon, and stomp down with his boots. All the weapons in Dead Space have a secondary firing option, allowing for a wider variety of attacks and strategies. Combine all these options with Isaac's two other abilities, the stasis and telekinesis modules, and you have about as many ways to kill the necromorphs as they have to kill you.
Another interesting feature in this game is dismemberment. Head shots and body shots are not encouraged in this game. In fact, doing so can make the necromorphs go into a rage, or in some cases release more necromorphs. Blasting, slicing, and shooting off an enemy's limbs will take them down much faster and save on ammo. Which limbs to remove is as important to consider as aiming for them in the first place. Shooting off arms does the most damage, but it's much more difficult to do. Taking out legs slows down enemies, making the arms easier to remove. It's not all that easy though, the necromorphs are fairly intelligent, and will tuck their claws in while they run, use ventilation shafts as a means to sneak up on you, and use loose team tactics. The enemy designs and behaviors make them some of the most disturbing and challenging foes in horror games to date.
Dead Space's environments and audio are what really make the game shine though. The darkness and deafening vacuum of space are so well represented in this game, it's amazing. Corridors are plastered with pulsating organic mass. Lights and power outages occur, leaving you with only your flashlight to guide the way. Malfunctioning doors slam shut in front of you repeatedly. But it's not only about the darkness and visuals. The vacuum of space is deafening, and you'll need to enter it several times. Since you can hear nothing but strained breathing as Isaac runs low on oxygen, you'll never know if an otherworldly terror is about to sneak up on you.
Dead Space is an instant classic. The game's environments and creatures are so well done it has earned itself a place as one of the definitive horror games of not only this generation, but previous generations as well. If you liked Resident Evil or Silent Hill, you owe it yourself to give this a try. You'll be watching the ventilation in your home for weeks.