Google announced on June 10th that it has deprecated support for critic review markup schema and structured data. Google said "we initially tested critic review markup with a group of site owners, and ultimately found that it wasn't useful for the ecosystem at scale."
Google added "This deprecation doesn't affect any other review features on Google Search. Feel free to leave the markup on your site so that search engines can better understand your web page."
A critic review is a snippet from a longer review article that a single editor has created, curated, or compiled for a publisher. Critic reviews use to appear in Search results with a snippet from the critic, the critic's name and the publisher icon, helping your readers to easily find the reviews and navigate to your website to read the complete reviews. You were able to supply critic reviews for the content types including local businesses, movies and books.
Google launched critic reviews in 2015.
Here is what it looked like as rich results in Google:
Forum discussion at Twitter.