The introduction is too long and bird riding is hard.
Update: I figured out what I was doing wrong while controlling the bird, so now it's less difficult and just boring. Also, the Wii remote is not reliably accurate enough to require precise movements of players when they're fighting nearly every enemy. Half of the time the controller doesn't know whether I'm swinging left vs right or up vs down, which is problematic when I have to swing one specific way just to hit an enemy.
Skyward Sword is a game that's more about its controls than its story, which is a bad place to start. When Myst popularize the use of the mouse for personal computers, it never felt like a game about clicking on things. Clicking on things was just a naturally intuitive way of playing. Everything in Skyward Sword other than sword fighting and aiming should have been simplified to not use motion controls at all, but Nintendo is still desperately trying to validate itself. If you can't use motion controls in a way that would mimic the real-world way in which you would perform an action, don't use motion controls for the action at all.
Update 2: The only difficulty I've experienced with this game is when the controls aren't responding properly. I nearly died during one of the boss fights because the game didn't realize that I was trying to stab the thing in the fucking eye with a thrust of my sword. I eventually strapped the controller to my dick and started doing pelvic thrusts instead.
Video games are dead to me. The last time I bought a new game was when GoldenEye 007 came out on the Wii, which means that a remake of what is largely considered the first great console shooter (never mind those who say "best shooter/game of all time") was the last game that I considered worthy of a week-one purchase—and even then I didn't pay full price because I'm cheap/poor. But then Aliens: Infestation came along and I had to rethink my life choices.