My personal opinion is that I honestly feel like I'm being a bit generous with the 3 stars.
I didn't hate the movie, but at the same time found myself looking around the cinema room quite often due to lack of an interesting story plot.
Action choreography was pretty cool, but the fight scenes were like re-living the early Assassin's Creed days where out of a group of multiple enemies only one would attack you at a time whilst the others would stand around idle.
The scenes themselves felt washy, and very far fetched. Yes I'm very aware it's within a universe where mad things can happen (it's cinema at the end of the day), but the fluidity and realism of most scenes just seemed a little dumb.
Put it this way..Suicide Squad didn't seem to do very well, there were some aspects I liked in it but overall it was a pretty weak movie. However I personally feel that Suicide Squad's script and story plot was still stronger than Birds of Prey.