What they got right: The character sfeel like they should in the world they're in, Captain Marvel's plan to beat the Evils
CLICK TO SHOW SPOILER seems to be based on the trick Mary played on him last issue, and the continuing storyline (as opposed to stand-alone stories or "trade padding" story arcs) between issues is something sorely lacking in the "Big Two" as of late. We knew
CLICK TO SHOW SPOILER Black Adam had to make his debut eventually, and how it comes about feels natural, not forced just for the sake of making it happen. Everything works.
What they got wrong: Once you get past the art style (which grows on you), the wacky comic tone (which to me should be in the "got right", but I'm thinking of others) and the fact that Mary is now a hyperactive little sister instead of Billy's twin sister (at least she's annoying in a fun way), not much.
This part depends on you: The "Monster Society Code" part is gone. Decide for yourself if this is a good thing or not. It was kind of fun, and I know the kids might have liked it (or not), but I don't miss it.
Recommendation: If you haven't been reading this comic because it's a "kiddie" comic, and doesn't have darkness, violence, or whatever else you think all comics should be, your no fun and I don't want to deal with you. Go in the dark corner with your evil Mary and your anti-life equation and be boring, no-fun-boy!