Twilight Princess' biggest problem is that it's hollow.
The largest (non-Wind Waker) Zelda map ever made, and the most visually intricately detailed - and there are what, three sidequests? Two of which give the same reward, which in itself is only really useful towards completing the third?
The most impressive and intimidating bosses in the series, and yet they're all easy as pie to defeat?
The most story-driven Zelda game ever made, and yet, still relatively empty compared to the tragic Wind Waker, the bizarre Majora's Mask and the melancholy Link's Awakening?
Twilight Princess tried to be the biggest Zelda ever, and somehow ended up being the smallest.