For us big Cloverfield fans that were super excited about the movie before its release, J.J. Abrams released secret Web Blogs, secret websites, secret commercials, that basically were all keyed together. They led up to the details of what took place in the actual movie. So if you actually watch the web blogs (I remember, there was a website that had secret VLOGS that you had to hack into, so you could watch the videos).
Anyway, if you watched all the Vlods, read the blogs, read the websites, etc, the movie makes TOTAL sense; However, if you didn't know about any of these, and just watched the movie, I understand that you most likely wouldn't get it at all. Besides that fact there's some big monster wrecking New York City.