I think it's RT score so far is somewhere in the 70's if you're into that. There's a lot of people praising it as a "love letter to comics and DC" etc.. and people praising Keaton and a lot of people praising Ezra Miller too.
There's also people who are saying the CGI isn't that good and that they are "sick" of all the multiverse shyt and others who are simply hating on it because of Ezra Miller
Which was gonna happen, there's no way some people weren't gonna use their reviews to go after Ezra Miller's behavior. That kind of comes with the territory even though it has nothing to do with the movie itself.