The movie The Thing had decent special effects for the early 80's. While not technically up to speed with contemporary movie effects, the scenes where people turn into 'Things' are still some of the most stomach churning visuals out there. These scenes in the game are not nearly as impressive, usually just showing some simple splatter effects as the soldiers turn into monsters. It certainly doesn't inspire the same dumbfounding fear as the creatures in the movie. I probably could have overlooked this had the game been trying for a Teen rating. But since that would have been a pretty vain attempt with this game, they should have just gone all the way. The good news is that's really the only downside to any of the graphics. The rest of the game looks wonderful.
While many of the visuals are just 'good' and pretty mundane to talk about, the facial expressions and body language are definitely something worth talking about. Since a corner stone of the gameplay is about people's fear and suspicions, behavioral animations can go a long way in conveying a good sense of atmosphere. Things such as characters looking around a little faster than usual, jittering, and increased breathing are very expressive cues as to your teammates' current state of mind, aside from the icons used to indicate a change in behavior.
As far as sound and music go, everything looks, err sounds, good. The quality of the sound effects is good. Everything sounds pretty much exactly like it would in real life, which is what you'd want in a game that tries to be immersive. The music is fairly theatrical, staying mostly in the background until cut scenes start.