I read a lot of reviews before buying this game - the last thing I wanted was a 5 minute wonder. Based on what I read, I decided to buy it, and I'm glad I did.
I bought this game for my just-turned 5 year old and it seemed the perfect age to introduce it. She grasped the rules quickly, so it was easy to learn and play.
It is not a long game. Players of Settlers of Catan might feel the resources are too easily come by, and too easily traded (you trade with the bank or trading post rather than each other unless you play the advanced game,) however it works well for a fast game and to keep the interest of younger children.
Yes the coco cards can heavily weigh the game, but not always. It didn't take long for my daughter to realise that it was definitely a good way to win! But she's also learned that it doesn't always guarantee a win and she now tries different strategies.
As for us adults - it's a pleasant enough game that we enjoy playing with our little one. And I like the fact that she's getting some basic strategy and rules that will help translate to Settlers of Catan when she's a bit older.
In summary - I highly recommend this for children aged up to about 8 (perhaps introducing it by age 7) , but any older and it would make sense to start them straight on the full Settlers of Catan game.