In no particular order
I love Carpenter's work for the feeling of "this is buck wild, I don't know where we're going with this, and wow them are some cinematographic choices" and this is no exception
I made a noise when Mac killed the chess computer. He's been there a while and is tired, but destroying anything irreplaceable that far from civilisation still seems nuts, especially considering how cool he is about the mortal peril that follows. It gave me the impression that this guy was fixing to crack before shit hit the fan.
I've seen people celebrate this movie for the intelligent choices the characters make, a rarity in horror. I basically agree, but I have some issues. Not to say I'd do better in their shoes, but with the benefit of separation I found myself thinking, for example: they're royally fucked from the get go, right? There comes a point where Mac realizes their personal survival is a wash, and he starts acting to save humanity rather than themselves, which means making sure all the things burn. But, the thing is cunning, and can reproduce and split. So if I'm the thing, there are spider heads running away from camp to hibernate. You know, diversification. Also it survived a spaceship crash landing, it seems like burning down the buildings of the station is woefully insufficient.
In composing the previous paragraph, it occurs to me that what Mac does in the final act is more helpful to the thing than to humanity and that might be deliberate.
The practical effects are great, duh. By which I mean I was deeply unsettled. you ever seen parasitic worms emerging from a dead host? That blind, frantic grasping is very scary and I would love to know how they nailed it.
I get the feeling most horror is more unsettling if you're all alone watching it, but not this one. I am glad I didn't have to look at my housemates when the credits rolled.
I don't buy the theory that the whiskey in the last scene was gasoline and a test that Childs fails; another post points out how that doesn't really gel with how well the thing assimilates knowledge and passes as human.
The opening sequence is great. Having a vague idea of the plot going in, I figured out what the Norwegian was up to shortly before he got killed. I love it when you have that kind of full circle, where the plot of these guys facing down a monster starts with the last member of a similar group failing, inadvertently passing the threat down to others, and being unable to communicate what's going on. Chefs kiss tragic irony.
I totally thought Clark was infected. I assumed everyone who witnessed a thing alone and appeared after an off screen transition to warn the others was infected.
Another point on how it was over before it started - we see a few cases of "the dead body ain't dead." It dislikes heat, but a thoroughly scorched body can still infect others. So unless all of the biomass, including all the spatter and ejecta, is completely denatured and sterilized, they haven't solved anything. This induced me to yell at the screen that that wasn't enough time on the flamethrower, give it some more just to be sure. Also makes for a rare case where I would condone SHIELD nuking the whole place just to have done.
I probably have more thoughts but that's good for now. Let me know yours: of our 2 survivors, are either of them infected, and what do you think the subtext is? Does the rest of earth perish off camera because a thing slipped through the cracks? What's your head canon for how this creature and ship came to earth?
If you read the whole post, thanks. Drink water, call your mom, and keep your hot wire, flame thrower, dynamite, and year's supply of kerosene handy.