For now I've only been through Gahreesan and Teledahn, and even though Gahreesan had some incredibly beautiful views (I love the outside), it didn't felt very coherent to me, regarding the puzzles (one "real" puzzle, and the rest was a game of hide and seek, as BJ said), and there also was one situation in which I got stuck forever
Spoiler:That's when you have to go back to Teledahn; I really had no idea the Ages could be inter-dependant.
I had to use a walkthrough here, which I find annoying, considering how I loved going through the puzzles in Teledahn.