Pretty Good.
It's as the title says. But really, I like where this is going. You should consider finishing the animation. As for sound, don't worry as most people nowadays has fast enough internets to load the sound as well as the animation in less time than it takes to, say, go to the kitchen to make a peanut butter sandwich.
Pick some good music, add a few more sound effects, possibly do a little voice acting, and extend the animation. I'm sure it'll be a great thing.
Though... I *was* wondering what happens after Batman gets grabbed. Please don't leave it up to my imagination.