Absolutely! I was there 3 weeks ago with my 7 yo - we arrive in time for the opening (10am) and stay until the last thing in the evening - and there's an activity every 1/2 an hour, but plenty of other things to do too.
Met another MNetter there with her 6 yo ds - and the two boys did most things together but somethings apart (which was absolutely fine). The restaurant is relatively basic but fine - food that children will eat, plenty of places to picnic as an alternative.
We've been every year for the last 5 years.... (when on holiday!)