Like I had mentioned many times before, DC has done an amazing job in the past couple of years with their original animated films. I've seen most of them, but Superman: Unbound is fairly recent. Unlike other Superman stories featuring Lex Luthor or General Zod, this one has the rather lesser-known villain Brainiac.
While not really a sequel to any of the previous stories, it's set in a time where Lois Lane already knows Clark Kent is Superman. While Superman and Lois struggle to make their relationship "normal", this won't be the greatest challenge for the Man of Steel. As a mysterious robot lands on Earth, and while he was easily defeated; Superman wants to know where he came from.
Superman doesn't have to wait long for an answer, as his cousin Kara Zor-El (Supergirl) had seen the robot long ago. Before the destruction of Krypton, Kara had seen countless robots overpower a city as on their home-planet (due to having a red sun) Kryptonians have no super-powers. Kara also tells Superman that the maker of the robots is Brainiac, and knowing that Earth could be next he intends to find the evil villain first.
Overall I really liked Superman's new tale. This had actually been the first time I really seen a story with Brainiac. While he's really over-powered, he does counter the Man of Steel fairly well. I also really liked Supergirl and the parts where she must find the courage to face her fears and doubts. Could have been more epic, but I can't complain too much.