Love the freedom you get in this game, a lot of the puzzles have great desings and I think the bosses are fun. I think the combination of the Zelda puzzles/feel/artstyle/music combined with the precise combat of Dark Souls and the amazing design of the book made the gameplay very well paced and progress never got boring.
The only thing I didn't finnish was the tower. The tower is something i respect, even though it's annoying that I can't 100% the game without googling the answer, I think all games should have something for it's die-hard fans.
Overall, very well executed game.