Warning: Spoilers Abound Here

Rating: 6/10 (4 July 2016)

There are quite a number of reviews of this movie and just as much talk on social media, so I'm not sure that I can say anything is truly a spoiler about this movie, but I am finding it very hard to share my opinion without discussing the ending, so if you don't want spoilers, read another review.
I really have nothing new to add to the noise, so almost refrained from writing a review, at all, but in my head there is a vast audience of imaginary geeks waiting to hear my opinion of each movie I've seen, so here goes.
85% of this movie is good (not great), then an ending comes along that doesn't so much ruin the movie as much as make you wonder if the whole thing was worth it.
I'll start with the positives, which are mostly the acting. John Goodman is very good in this movie, playing a man who may or may not be completely psychotic. He is, most definitely, a conspiracy theorist who spent years preparing an underground bunker that has now come in handy. He has "rescued" a young man and a young woman and is intent to maintain his own rules and order in this underground kingdom of his. Goodman carries this role excellently, wavering between kind-hearted and terrifying and playing both with equal finesse. We are left unsure, as viewers, for most of the movie whether we believe this man has good intentions, or if there is something far darker lurking under the surface.
Winstead, as the young woman who winds up here, in this bunker, after being rescued from an accident. She is able to portray an every-man in this role, making us question our own reactions to the events unfolding. She begins the movie just after making a life- changing decision that ends up having impact on the events that will unfold later. After walking up underground, she goes through a natural array of emotions, at first terrified she begins to accept the situation, but never so much that she gives in to it completely. Always wary of her host, the events unfold from her eyes. She is believable throughout the movie, showing emotion when necessary, but also playing strong and determined.
The events of the movie are tight and riveting. Most of this movie is a suspenseful thriller that keeps the audience on its' toes and engages the viewer throughout as the plot twist and turns. If there is a negative to throw on it, it's only that the movie feels not entirely fresh. It's not necessarily a rehash of any one movie, but nothing feels entirely original. Yes, it's well done, but it's a well done amalgamation of plot devices that we've all seen in horror and thrillers before. Even if I removed the ending of the movie, it's still not a 9 or 10 in my book because there is nothing revolutionary here, other than excellent acting.
Then, we get to the ending. You could say it's a twist, but I think we all saw it coming, right? Whether or not you believed any of the alien conspiracies that Goodman was throwing about, we know the franchise name, we've seen the trailers, we knew that there was "something" out there, so that suspense was pretty much ruined. That's fine, in my book. Even knowing that she was going to get out and there was going to be something monstrous, it could have been done better, instead it turns cartoonish.
I had high hopes at first. The first glimpse of the ship and the ensuing chase by the alien creatures pack some scares and continue the tension of the movie. It was promising, then things fall off the rail completely. Am I really to believe that these aliens crossed eons of space and time and conquered an entire planet (or at least country) with spaceships that were so weak they could be destroyed by one molotov cocktail. I mean, I've seen some "heroic moments" in sci-fi and horror where the hero conquers the monster with the tools at hand, but this was really stretching the limits of what I was willing to believe.
So after an hour and a half of tension and the constant fear of what was lurking out there, it all wrapped in about five minutes of chase and our heroine, of course, winning. Then we get all INDEPENDENCE DAY and find out that there are pockets of humanity winning this war. Our heroine, who had given up on her life at the beginning has now decided that her ordeal has given her the courage to join the resistance rather than head for safety.
As many have mentioned this movie very much felt like it was written as another film and someone tacked on an alien ending. If internet rumors are to be believed, then this script floated around Hollywood under another name for quite some time before being bought and having the Cloverfield name appended to it. It doesn't matter what Abrams wants you to believe about there being other aliens in this universe. The script was never written to be a Cloverfield sequel and any attachment made is artificial and came secondary.
There was a good movie lurking in her somewhere. Modern Hollywood, unfortunately, doesn't want to put money behind anything that is not a sequel, reboot, remake or adaptation, so what was a promising thriller becomes an artificial sequel to a movie that needed a real sequel five years ago and the end result feels fake and forced.