ABZÛ falls into the category of "walking simulator" where gameplay is sacrificed for the emphasis on the experience; which in this case, is the art-style and sound.
You play as a diver, swimming through the sea alongside many species of marine life. It is often very colourful, and the shoals of fish or individual creatures swim believably; the developers have obviously put a lot of effort into this. The aesthetics and sound design are incredible and the positive reviews are for this fact. However, it is definitely the case of all style, no substance.
There's no written or spoken dialogue, and the story is pretty much non-existent, or at least it is so abstract that it's hard to understand your purpose in the world. There is a hint to who your character is, and you find some underwater temples with wall paintings, but without studying this in more detail; you aren't going to understand the relevance.
I expected this game to be more like Endless Ocean, where you discover different species while you are amazed at the beauty of the ocean. You can grab hold of the larger creatures and the game will tell you what the species is, but there's no bestiary to fill in; so no sense of completion or feeling of achievement. I expected a much larger sense of exploration too, but you are guided down linear tunnels, or small caverns; so it almost plays itself.
There is no failure in the game since you cannot be killed. There is a section where you can be zapped by these pyramid objects if you get too close, but they are just a hindrance rather than posing real danger. It's not a terrible thing, but when the game showed a shark attacking my mechanical companion, I really thought that was the game introducing me to a stealth section; but it was irrelevant.
The game felt really repetitive too. You will move down a linear tunnel, led to an open area, activate something in order to move on, then pushed through a current to the next area; then this basically just repeats. I felt like I'd seen everything after 20 mins.
The game is extremely short too; I think it was around 1.5 hours. I was a bit dumbfounded when the credits began to roll since the previous section only seemed important due to the change in intensity of the music. I didn't feel like there was any progress with the story/any satisfying revelation at that point.
If you like these type of experiences where you can marvel at the atmosphere, then ABZÛ will be of interest. For those wanting a great story or any form of gameplay, then I can't recommend this.