My 8 year old daughter received this game for Christmas and loved the first 4 days, but on day 5 some men turn up and start scoring how well you are doing, if you don't get a fantastic score from the start of the day they tell you to start again and you are sent back to the start of the day (and have to scroll through pages of conversation which takes ages). I've tried helping her get past that bit but even I can't get past it! It's incredibly frustrating as the men don't give you enough time to ensure the entire park is as it should be. The only option is to start a new game and try again, which is silly. Poor game design in my opinion.
I would not recommend buying this game for a younger child as they will simply find it annoying and frustrating, not fun. Instead I recommend My Pet Dolphin 2 which is a lot of fun and lets you look after the animals, play with them, help babies find their mothers and find treasure. None of this "men in black" coming to close you down business.