Cut the pretentious crud. This film is obviously intended to entertain a younger audience, and it does a good job at doing that, while somewhat tactfully putting in some jokes for the parents. No, it's not spectacular. If you watch this movie expecting something "Grade A", you're not going to get much out of it.
The plot: generic, predictable. But obviously so, considering it's called "Gnomeo and Juliet".
The cast is an oddball compilation of respectable actors, with the exception of the obscure addition of Ozzy. But what is really keeping this movie going is the cuteness of it. That is the selling point, and what makes it most appealing. If you go into this movie expecting something more, you will be left disappointed. So I suggested you loosen up, look for a laugh, and you'll enjoy it more. It's not a bad film.