You can now give a simple “thumbs up” if you like a comment or report it as spam if it’s rude, off-topic, or otherwise egregious.
This replaces the previous system where you would pick between a thumbs up or down to rate someone’s review. It’s clear that Google is trying to clean up the Play Store reviews. Giving it a “thumbs down” is a little ambiguous, and could imply that you just disagree.
I spotted the change on my Nexus 6P right away, so this could be a rapid server-side rollout. From the Play Store, go to an app’s page and scroll down to select Read All Reviews. Then you’ll see the above list.
Why this matters: Google has made a number of changes to the Play Store lately, such as adding in-app promo codes and more prominently highlighting certain user reviews. It’s always a work in progress in order to improve the experience for developers and Android owners, so keep your eye open for new stuff.