Well I've had this game for a few weeks now, I imported it from Europe and it is excellent. The concept is simple but it works extremely well. Your a diver and are free to explore the ocean at your own pace. Interacting with fish is easy to do and requires you to swim up to them and pat them by waving the remote. You can also feed them or blow a whistle to find out more information about them. You can use your own soundtrack via an SD card as well which is a great addition. The dolphins that you can recieve for partners are pretty cool. You can teach them tricks and also go diving with them. Another handy thing these guys do is help you find more different species of fish. So far I've only encountered one whale and have only had enough time to play for 5 hours but this game is definitely perfect. You can switch between third person and first person view whilst diving as well.
The controls are simple, all you do is aim where you want to go and hold the B button. The graphics are impressive with the component cables and under water the visuals are gorgeous. On the boat the visuals arent too bad but not as good as they could be.
Sometimes you may be required to take others diving to find a certain fish and this is cool as if you show them the fish then you can upgrade your diving gear.
I love this game and it is a must have game at this price. It is the most relaxing game I've ever played and you can't die which makes replaying a breeze.