I got dragged to see this by my cousin today (she's old enough to know better but wanted to see it because she loves cats).
Good completely mindless nonsense - and how many movies have a villain called Mr Tinkles?
If you can deal with being in a cinema full of kids - I should have borrowed a couple really - then it's an enjoyably mindless way to pass an afternoon.
Personally though, if you've got to go and see one of the summer-holiday movies then I'd go for Shrek which has more in it for adults and older kids.