I just bought the game, and my 6 year old son absolutely loves playing it. Before then he saw me playing it online and asked a lot of questions so when I bought it he already knew most of the game play.
We have played it 4 times since I got the game 2 days ago and if it was up to him we would have played it even more. The last time we played I introduced the action tiles to him for the first time. He still hasn't grasped all of them, but he really likes the possibilities they provide.