I haven't played it in a few years due to no longer having a Wii and my GC not having enough juice left in it to read the GC version disc without a disc read error, but the game did disappoint me. I played it all the way through, yes, and enjoyed it, but there were a few key things that failed me (however, I also wasn't a fan of Wind Waker, and have since come to like it a lot more than I used to -- maybe the same will be true of TP).
1. The difficulty: Everyone already knows about this. The combat difficulty, especially, was far too low to hold my interest. And with the exception of maybe two enemy types that appeared infrequently, the optionally-learned combat moves didn't really make combat any easier, since combat was already pretty much as easy as it could get. The one thing I'll always remember about combat in TP is waiting ages for bokoblins to even try to attack me... then when they did, they were too slow.
2. The graphics style and animation: The graphics style was actually really, really good. However, and perhaps this is unique to me, it made me sleepy. Not from eye strain or anything like that, but it just had some quality that induced boredom in me, I guess, when I looked at the game. I suppose it would be like playing a long game with Norman Rockwell-esque graphics. The only problem I remember having with the animation is that Link seemed way too stiff when running and jumping (OoT had better running and jumping animations, in my opinion). It's like Brawl's Ganondorf model running: It looks like he has a stick/metal rod rammed up him. Finally, the Master Sword... it looked too long.
3. The sound effects: They were also really, really good, but there was something about several of them that I didn't like, and some of them contributed to that feeling I got from the graphics (specifically, the text-writing and press-A-to-continue sounds, but maybe also the little music you get when opening chests and getting items). Superb music, though: Lake Hylia, Midna's Lament, and the Serenade of Water remix stand out in my memory as some of the best songs I've ever heard in a game.
4. The characters: It was not a good idea to introduce so many characters and then practically throw many of them away after just a little bit of interaction. Colin and company, I'm looking at you. The people who move on the castle to help Link at the end didn't get nearly enough screen time, either. And while I don't dislike Zant's personality change as much as others do, the cutscene where Zelda drops her sword, and the battle with Zant really do clash. The former made him out to be a much cooler villain than he ended up being.
5. Chest contents and rewards: Rupees, rupees everywhere, and not a thing to spend them on. Wait... armor, in an already extremely easy game, that spends my rupees for me? Why?
6. Side quests: The good ones -- where were they? I didn't even finish the Poe Souls one, since the game had no equivalent of the Sun's Song, to my knowledge, and I wasn't going to scour the huge world again, waiting for nightfall at each locale, just to find 1-2 more Poes for some golden idiot. Catching bugs was more fun, but the word "fun" still only loosely applies to it.
7. Size/emptiness: The whole world, but especially Hyrule Field, was guilty of being too big for what was actually in it. Now, I loved the size of Hyrule Field, but there just wasn't enough to do in it. It felt a bit like the repetitive sailing that everyone complains about from Wind Waker.
Those may or may not be all my complaints, as it's been a while. I think the dungeons and bosses didn't disappoint me, however, and in a Zelda game, that's a very good thing.