I know I'm about 2-3 years late on playing this game, but it took that long to convince myself to take up this survival horror.
The famed "Planet Cracker" USG Ishimura has been incommunicado after sending out a distress signal. That's where Isaac Clarke enters the picture, having an interest in not beginning repairs, but also in saving his girlfriend Nicole from the large and seemingly dead ship. However, things aren't as dead as they appear to be.
The good: Firstly, the scare factor. This being my first horror game, it scared the pants off of me a lot of times. It wasn't only the necromorphs pretending to be dead or babies jumping off ceilings to stab you in the neck. The game got into my head and played on my fears through little atmospheric sounds: a crew member you meet banging his head against a metal pipe, or the constant, small whispers of "Isaac" that can be heard throughout the ship. The use of ammo also left me feeling truly alone, as killing enemies has to be done precisely and effectively. No bullet spraying here!
Secondly, the graphics. Despite the age of the game, the graphics don't seem to be dated at all, and move quite fluidly.
Thirdly, the story. I knew from the beginning that things weren't what I expected them to be, but holy plot twists. What you thought was the cause of all your problems ends up being what was preventing everything to begin with.
Fourthly, the slight RPG-style system. One can buy power nodes to modify one's suit, weapons and modules to take out enemies a lot faster.
The not-so-bad: the controls. I was never a big fan of 3rd person shooters, as it places the camera too close to the back of the person's head and leaves less than the full screen for shooting at targets.
The vast array of weapons. There's really no reason to buy anything else besides the plasma cutter, as a meager inventory only allows for an insufficient amount of ammo to be carried for each weapon, not to mention air tanks and med packs. If you play your cards right, selling most of the ammo you find will generate enough money to keep your suit and cutter well modified.
The characters. I felt like Hammond's and Daniels' bitch, running around doing everything they asked me to do. At least with Bioshock, there was a plot point to doing it, but with this, it just felt like the NPCs had nothing else better to do than sit in their little confined safe room, ordering me around the ship.
All in all, a great game that I could play over and over again.