The second mistake about the game's title is that unlike the movie where there is only one "thing", there are many "things" in this game. Something like the sequel to the movie Alien (which is called Aliens).
Anyway, here is how the game begins. You are the leader of the rescue team sent to the research station to find out what happened. When you found out the real reason behind the disappearance of the previous crew, you were left stranded and the whole game's objective is to escape.
This 3rd person perspective action/horror title has some new features never before seen in a game. The most unique feature is the NPC's (non-player characters) which you will meet throughout the game that can change emotions. For example, if you rescued a NPC, it does not necessarily mean that it will cooperate with you, this is because they are afraid that you may be one of the "things" (Just like the movie). So, in order to gain their trust, you must give them weapons or some ammo. But the emotions will change dynamically depending on the situation. There are a few NPC's that you will encounter : medics, engineers and soldiers. By far the most useful and most important person is the engineer because some doors can only be unlocked by them. So, protect them well otherwise the mission fails.
Another reason this game is called the thing is that the NPC's that you will meet will sometimes turn into the thing. Unfortunately, unlike the movie where you do not know who would eventually turn into a thing, it is very predictable in this game, so the tension and suspense is mostly lost here.
There are many different kinds of things that you will face : small spider-like things (plenty in this game), Bull things that charge at you, hanging tentacles and the above mentioned human turned things. There are also boss levels which varies in difficulty but all of them have the same strategy : shoot first and burn them with the flamethrower. (which can be difficult at first)
In short, the story is a bit predictable and almost similar to Half-life. And the saved game system follows the Resident Evil style (can only save at certain areas). But gamers expecting a Resident Evil style of gameplay will be disappointed as this game is purely action and has very little puzzle solving and key hunting. A good game to play if you are a fan of the movie but don't expect to be frightened by it.
pros : good action, varied objectives
cons : NPC interaction not implemented well, not enough of that haunting soundtrack (dum-dum......), short.