Personaly I would have said 10-12 years old. The official age range will likely be 10+
That is what I would have said too - if I had to make an official statement.
I also agree that the game is more complex than Pirate's Cove, but you don't need to throw all the rules after your kid when you play it the first time.
I am convinced that the game can be quite enjoyable even on a more basic level, and the game can then be expanded as father gets beaten!