I am still unsure of whether the invention of found footage films was a decent, creative idea or an absolutely horrible idea. I suppose it's good for the horror genre (one I've never been a fan of), as the shaky cam and angles allow for more mystery and jump-scares. But it's never something I've been a big fan of. It's rare that one will come along that I'm even willing to try to watch. And usually, they don't even fall under the horror genre.
Cloverfield doesn't exactly fall under the horror genre. It is a monster movie; but I feel like it really is just that. It isn't really a horror film, but it's not really an action/adventure film or sci-fi film either. It's just a monster film about a monster that attacks New York City and causes chaos and destroys a lot of things (as you can tell on the poster alone).
And really, that's the basis of the plot. Found footage films have never been strong on plot in my experience. The characters of the movie? And their plot? Not much to say there, really. We spend a doggone slow first 20 minutes going through a "going-away" party for some guy named Rob, while he fights with his ex Beth, and some guy named Hud films everything. The monster attack interrupts their little party, and they and some others are caught in the fray as Rob has to go back across town for a trapped Beth while the military wages war with the creature.
Cloverfield does have its moments. It does have a couple of startles, and the monster itself is certainly an interesting creation. Despite it being found footage, there are actually a couple of cool camera shots. Unfortunately, Cloverfield is victimized by the various found-footage cliches (in my experience): annoying shaky cam, terrible dialogue, lack of overall plot, annoying characters, and well... you get the point. Even if this is on purpose *because* it's intended to look like someone filmed it on their camera, it still doesn't really excuse it.
One thing that Cloverfield does have going for it is the mystery element. There are various questions that are not answered (and some that are actually raised) such as the origin of the creature. Whether these things will be "answered" or not in the "sequel" 10 Cloverfield Lane will admittedly be interesting to see. (Wait, am I actually interested in a found footage *sequel?*)
If you're a fan of the genre, Cloverfield will be a thrill ride all the way to the end (except for the first 20 minutes, which no one could actually be "thrilled" during). For everyone else, there's still really no reason to dismiss it other than its found footage nature. I enjoyed watching it once, but I don't know if I'd want to again.