Yep, a starred review. Apparently given to “outstanding books”.
Publishers Weekly’s full review can be read here, but here’s a nice taster:
Barnett gleefully blends Victorian-era characters with steam and clockwork technology in a “steampulp” romance of supernatural adventure…even readers who don’t usually love steampunk will gobble it up.
See that? “even readers who don’t usually love steampunk…”.
That means you.