Addictive and awesome.
The puzzles start out easy and get harder as you get further into the game. Toward the end, you have to use every tool in your inventory to figure out what to do next. At no time did I feel completely frustrated. Sure there were several levels where I had to repeat the same jump without getting killed, but that should be expected. But I never shut the thing off cussing about how hard it was.
Even the final battle with the ultimate boss was challenging, but not impossible. I think this is the one thing that makes LoZ:TP a "great" game. It is challenging, but not impossible.
It's strange that now that I've completed the game (after 57 hours of gameplay), I'm feeling homesick. As the final credits rolled by they showed rooms and environments that I still had fond (and not so fond) memories of. I found myself thinking "Oh yea, I remember descending that staircase", or "I remember having to navigate that gorge." Now I miss it.
Sure, I could go back and get all those Poe Souls, or collect all the heart pieces, but what's the point? Fortunately, the game can be finished without such OCD behavior :-)
I really enjoyed this Zelda title and look forward to the next one.