Also, 'dat music
After getting snippets of Dragon's Crown over the past six months, we're now getting the first lengthy vignette of practically everything the game has to offer compliments of an E3 trailer. From an in-depth look at the quest system, to how experience works, to multiple set-pieces and action portions, this trailer should placate you until the game's launch.
If you want to go in fresh, I recommend not watching this amazing video. Also, the dancing mouse returns. Hell yes.