If I understand correctly 10 Cloverfield Lane started out as a simple unrelated low-budget thriller under the title The Cellar (and later Valencia), where it was reportedly filmed and completed, but left on the shelf after issues with the production company. Producer J.J. Abrams eventually got a hold of it and had it re-written (and later filmed) with potential elements that would loosely connect to the Cloverfield universe.

Regardless of the familiar name in the title and the supposed connections to the first film, this is best viewed as its own movie, because anyone going in expecting an actual Cloverfield sequel will be greatly disappointed. In fact, it's essentially just as it's depicted in the trailer--a bottle film centered on just a few people in a survival bunker. Despite the underground shelter theme being used a lot over the years, this managed to stand out pretty well thanks to some great suspense, use of sounds, and an excellent performance by a very scary and intimidating John Goodman, who you (nor the characters in the movie) can really trust.

John plays a conspiracy theorist/survival nut named Howard, who claims to have found Mary Elizabeth Winstead's character on the side of the road after a violent car crash. She awakens in the bunker, where Howard reveals that the outside world is no more (thanks to some kind of attack) and she's much safer with him and another man named Emmett. The question of whether he's telling the truth or just batshit crazy is brought up quite a bit, ultimately resulting in a surprisingly decent mystery thriller.

Things come to a boil in the third act, eventually leading to the big reveal in the last 15-or-so minutes, where audiences are either going to love it or hate it, but either way it takes quite an interesting turn. I personally liked it, but it did seem a little tacked on and didn't quite fit the rest of the movie. It's still an enjoyable watch, though if it weren't for John Goodman's performance I don't think this would've been nearly as good.

Fans looking for monsters and lots of connections to Cloverfield will be greatly disappointed, because this is an entirely different movie. This is basically just a small thriller with an interesting mystery behind it and I personally think it's worth a look if you go in expecting nothing more than that.