I initially gave this movie 4/10, but as I wrote this downgraded to 3. I'd say this movie would be ideal for anyone between the ages of 5 and 9. I'd not buy it on DVD except from the bargain bucket, or watch for free on regular TV. I regret having spent good money to see it at the cinema.
We saw this at the cinema as a family; we are middle-aged parents with a son, 6, and a daughter, 4.
We adults thought it was slow to get started but managed to pick up a little bit of pace. It was quite predictable with the same jokes repeated, and there were no plot twists at all to give it any interest. The bored teenager role was acted with little imagination, the girlfriend just about imagining a soupçon of character. Brendan Fraser managed to make a reasonable deal of a weak plot, and his wife Brooke Shields had a few moments of believable acting as a wife.
The script writer lacked imagination, the budget was probably quite low too, there were times the poor CGI punctured the suspension of disbelief (I imagine this would not be one to enjoy on blu-ray unless they fix things up in the transfer). One novelty was that the animals didn't speak, instead thought bubbles appeared with pictures. If I was being cynical I'd say this was as much a way to avoid the costs of voice character actors and dubbing into foreign languages as to give the movie a twist.
This could easily have been an episode of a any standard sitcom about a family relocating to the country, and could have been edited down to 45 minutes... and then perhaps the reuse of jokes might not be so bad, but they quickly became stale.
So, the movie failed from an adult perspective. Did it succeed to keep the kids entertained? Our 6 year old enjoyed it, he's at that age where adults being stupid, animals being smart, and lots of mess and stink are funny. He's able to follow quite complex dialogue so was able to grasp the point of the movie.
Our 4 year old found it hard going, as it was slow to start, there was too much dialogue with too little action, she enjoyed the slapstick humour, but was frequently restless - she'll re-watch Finding Nemo with more attention and she's seen that 10+ times!.