So off the top I think the art style will throw off some, it's clearly made with the intention of a more retro look, reminiscent of 60's cartoons with general quality of life changes to make it better suited to modern audiences, which I personally found to be quite beautiful. I wouldn't want this art style for all future DC animated films, but it seemed well suited to the nature and tone of this film.
Storyline wise there is nothing particularly interesting about it, it's WWII based so it's mostly about punching Nazi's & stopping evil plans and I don't think it's a spoiler to say that, it's simply what the Superhero WWII genre is.
What's interesting or atleast refreshing about the film is it allows its heroes to be vulnerable, flawed, and make mistakes. Yet despite any shortcomings or fears they may have they persist on, it's the inherent part of what makes a hero courageous, far too many modern heroes, particularly with respect to female heroes aren't allowed to show weakness in any respect. A hero that shows some measure of vulnerability or is in someway flawed is always more compelling then the always perfect & virtuous hero who can do no wrong.