First of all, the film was more than good, in my opinion and, for the people who like to see a good or more than good movie, I recommend buying a ticket or the DVD release or just rent it. As a medium spoiler, I'd say that, plot wise, it reminded me of "Law abiding citizen", with the first three quarters of the movie full of suspense and plot twists, and the last act, a little rushed and over the top. And that justifies the two penalty points I gave to this movie, one of them just for the exaggerated use of a bottle of good brandy.
As for "10 Cloverfield Lane", I can say it offered just the things you would expect... from a movie you really don't know what to expect. A thin trailer, with little to no information about the plot was, in my opinion, was a clever move and made me watch it. And, to be honest, except for the final act, I was more than satisfied with the emotion, the tension, the acting (great for two of the main characters, kinda OK for the other one), the way the director played with my mind and feelings about the characters and the way it builds them. You expect them to be capable of doing the things they do in the movie. For once, a complete looser at the beginning of the movie doesn't become, inexplicably and over night, some kind of Macgyver/guerrilla fighter at the end. It's a movie you can't forget really easy.
Now, for the part that I'm quite annoyed with: the alien mayhem expectations that make this movie "baaad"...
I've seen a lot of reviews and opinions about how bad this movie is, about how much of a mixed up plot nonsense is and about the fact that most of them where "waiting for something to happen". Well, as I mentioned before, a lot of things happen, just not the ones you would expect. And, as I've seen, the upset and disappointed moviegoers were, mostly, the ones that expected to see a sequel for Cloverfield. Well (spoiler alert) IT'S NOT! It's a movie that tells a story happening during the events of Cloverfield and that is the only connection to the original. It can be taken as a standalone film, for that matter. And, as I said, a quite good one.
In conclusion: if you expect monster aliens fighting military helis, explosions, guns and all that Michael Bay stuff, then skip this one. On the other hand, if you expect a good thriller (with some added Sci- Fi at the end), good acting and disturbing plot twists, then it's the kind of movie for you.
P.S.: I'm not saying anything about the plot, because, just as one reviewer said, "the more you know about the movie, the less interesting it will be".