Its beautifully hand-drawn animation is eye-catching enough, but the gameplay is what really grabbed me. This is a game about social interaction, about perceiving non-verbal queues and acting appropriately on them. Observe!
The trailer gives you a sense of the story, but not the way the game is played. For a little more on that, I suggest you check out the article on Kotaku from Tina Amini.
The Act is built around using our own social intuition to navigate Edgar, our hero, through a number of situations. It's well executed, classy, and funny. You can pick it up from iTunes for a measly $2.99. For more info, head over the game's website.