The most unusual game I have ever seen, it immerses you in another world.
If you want something that will get your blood pumping, and your adrenaline skyrocketing, then put this game down right now. You can't lose this game. If you want you can completely ignore any sort of objectives or directions.
Why would you want to play this game? I honestly can't answer that question. I'm not sure why I personally find it so fascinating. You could say that there is certainly elements of collecting and exploring, but there is more to the game then that. The beautiful music, combined with the fascinating landscapes draws you in, while the mysteries of the deep make you want to keep exploring.
With creatures like the 150 foot long Praya Dubia, or the 7 feet long, 10 feet tall Mola Mola, or even the tiny Fangfish, with teeth almost the size of it's entire body. The best part is that these, and every other creature in the game (with a sole exception), are all real. All the dive spots are based on real diving locales, and the creatures have realistic appearances and habitats.
As I'm writing this, I'm looking at what I've written and realized that I can't do a game like this justice in a review. It's strange, quirky, unique, and beautiful.
I understand that many people would not like this game, but I am strongly recommending that you at least rent this game, because you may just find it fascinating.