Pros: 
- Incredibly atmospheric; I love all the smoke in the environments
- The lighting is fantastic 
- Some pretty cool weapon designs 
- Rewards the player for exploring, and trust me, I love games that let you explore 
- Flashlight charger 
- Some pretty chilling parts  
- Killing a dude with a throwing knife
 
Cons: 
- Numerous glitches make some sections of the game incredibly frustrating and more difficult than they should be, especially when you're trying to take the stealthy approach. There were numerous times when I'd chuck a throwing knife directly into an enemies' neck, and instead of killing him, the knife would "disappear" and he wouldn't even respond to it. 
- Frame rate issues, especially if an explosion went off. Slideshow central! 
- Inconsistent AI. Sometimes they were fine, other times they were flat-out dumb, and other (more frustrating) times they could see THROUGH WALLS! 
- Somewhat anti-climactic ending. 
- Some of the enemy types kinda killed the vibe for me (Ex: the amebas) that I felt didn't fit into the story or atmosphere at all. 
  
I certainly had fun playing this game; I really got sucked into it and there were some concepts that intrigued me. Unfortunately, the amount of bugs and inconsistent AI almost drove me to insanity during certain sections. When I first saw shots of this game, I figured a Fall 2010 release, and I believe they should've shot for that time period. I felt the game was rushed in a way, and that extra time could've been used to fix the technical aspects and overall polish.
 
Overall Grade: B -  
 
Feel free to comment and post your Pros and Cons.