I should start by saying that I hate the traditional Sims 2. My wife loves it, but I find it boring. I also didn't like any of the Sims games I've played on console so far.
But, Castaway is grabbing me, and pulling me in.
You are in direct control of your Sim, and use objects by walking up to them. You are shipwrecked on a desert island (actually a group of 3 islands) and the ultimate aim of the game is to find your crew, carve out a life for yourselves on the island, and eventually, find a way off the island.
There are lots and lots of areas to explore, and the variety is nice. Beaches, Jungles, Plains, Caves and more. The graphics are good for the Wii.
The best thing about the game is the way that you have to collect resources and invent / build pretty much everything, from Shacks to Beds, from clothes to a stove, you make it all yourself. This includes food, where you start by eating coconuts and bananas, and progress to dishes with 4 separate ingredients, all of your choosing.
I don't want to give too much away as half of the pleasure of Castaway is discovering things yourself. All I will say is that it's a very enjoyable game, even if you don't like the traditional 'dolls house' style gameplay of the Sims 2.
My only real gripes are:
1. You can only have 1 savegame. So if my wife wants to play it, we'd need another Wii!
2. When there are lots of objects close to you, it can be a pain targeting the one you want.
3. No multiplayer elements of any kind.
I'd give this an 8.5 / 10 , with survival fun for all ages. It's even semi educational due to the logic needed (I'm hungry so I have to find food for example) to survive. I think 5-8 year olds, as well as 40+ year olds, will find something in this that they will enjoy.