Magic Planet is great for the kids. We frequently take our daughter who is 18 months old, she loves the little stationery rides, and the carrousel. I personally think the rides are quite expensive for what they are, and how much they are in the UK.
Downstairs in the food court, there is a section for the kids to climb around in, which you can pay entry for with your magic planet card. I think this is good value for money, and my daughter enjoys having a run round there, although I find its very hot, and they need better a/c.