With the first year of "Supergirl" behind them, Michael Green, Mike Johnson and Mahmud Asrar jump back to the eve of Krypton's destruction for "Supergirl" #0. It's a decision that makes sense; while just about everyone knows Superman's origin (even if they've never read a "Superman" comic), the number of people who know what Argo City is or who Zor-El was drops dramatically.
That said, most of "Supergirl" #0 is a very standard, by-the-book retelling of Supergirl's origin. Green and Johnson, perhaps deciding that something which wasn't broken doesn't need fixing, have left it pretty much intact. Krypton is about to be destroyed, and her father (Superman's uncle) sends her away in a craft to survive the apocalypse. There's understandably little drama in the story, since after all the reader already knows the end result; Krypton explodes, Supergirl survives. Aside from one surprise character's appearance in "Supergirl" #0 (no doubt part of a future storyline), I think long-time comic readers will find themselves not batting an eye at "Supergirl" #0. It's so familiar.
Asrar's art is nice to look at. He's good at drawing Krypton's technology and general alien nature; it's that post-modern future look that we all thought the future would someday resemble, lovingly brought to life on an alien world. Pages as simple as Supergirl floating in a tank in an Argo City lab are pleasing to the eye and attractive, and it's a reminder to me that Asrar's been a good choice for "Supergirl" in general. I'm still not 100% crazy about all of the redesign of Supergirl's costume, but there's no denying that she has the best cape in all of DC Comics and those boots aren't too shabby either.
"Supergirl" #0 is ultimately running into the problem that so many DC #0 issues this month are; rather than occurring at a natural part in the series narrative it's just randomly getting dropped into the mix. Green, Johnson and Asrar do the best they can with the directive, and the end result is perfectly fine. But it's too bad this couldn't have appeared at a more natural point in the series; this could have been a lot more memorable with the right placement.