In short, it's Wind Waker on iOS. The controls are about 95% perfect. The music is phenomenal. The depth is about where the GBA Zelda's were at. The world is broken up into islands, some small, some larger. Even the biggest I've gotten to is fairly small, but dense with content.
Basically, the question of whether or not to get Oceanhorn should really only depend on one question. Can you enjoy a game that is a flawless rendition of the most famous game series of all times? If you can, get it.
If you're going to be punching your iPhone/iPad when you discover that you have to go find the 3 pieces of the magic amulet that broke apart (and of which you're the owner of one of those pieces) while searching for heart containers and throwing clay pots at Chu-Chus, then don't.
Where GameLoft pushes out hastily made copies that are akin to Game Informer envelope art, whoever made Oceanhorn (some sort of wolf logo, who gives a shit) is more like the dude who spends hours copying the masters to get his technique just right.
It's a great game and if they had decided to break away from the Zelda thievery, it would easily be the best game on iOS. Like, ever. That adherence to taking everything Zelda has done holds it back, because goddamn is it ever fucking blatant.
But everything else about it is straight 10/10.