Not terrible, but a bit too slow. Too much character development and build up made it kinda boring, and the scenes with the shark were just OK.
For a giant shark with a beach filled with people, it was a surprisingly low eat count, lessening the terror. It didn't help that they tossed in two tired tropes, a dog and a kid, where they try to get you to bond with them in the 10 seconds you see them so you care about them when they are in peril. Spoiler: you don't care.
Also, there is a scene at the climatic end with helicopters that was so ridiculous that it was laughable. Spoiler, no, it had nothing to do with the shark (which is sad.)
That said, there were a number of parts that were (intentionally) funny. But, for the most part, I got to the point where I was waiting for it to end. 6/10