For the mere 2 hours it takes to finish Abzu, forget about the usual nitty-gritty of game mechanics, relax, and just try to enjoy the ride. The game is absolutely gorgeous. Striking colours and jaw-dropping underwater vistas, coupled with some amazing animation, and the music is equally powerful. If you're part of the "but it's not a game" crowd, nothing I can say will change your mind, but this is a just chillout game. It's made to captivate the senses rather than test your skill in anything, and that's fine. Just like Journey, which had the same director, it's a relaxing and beautiful experience that is perfect to play while high.
I didn't find the second hour to be as intriguing as the first hour though. The game takes a darker and slightly more insidious tone, which is fine and everything, but I was enjoying the more colourful and peaceful nature of the first half. I was just hoping for more of that to be honest, and while I understand the reason for the change, I felt it was a shame that it had to go down that route. The game has a point to make, but it's a little hamfisted with it.