That was definitely interesting. I haven't seen any other hack series or played game, but liked this one. First thing i noticed was great quality of animation and character design that pleased my eyes.
I didn't notice anything special in voice acting, decent ones what you easily forget. But music totally kicks ass, especially OP. Background music improved a lot some scenes.
Story didn't fail either and overall first episode was enjoyable, one of few action series i have liked so far this season. Looking forward to see more.