Will Beall, writer of Gangster Squad, also wrote an as yet unused script for a Justice League movie. That should come as no surprise to anyone who watches Gangster Squad. This is as much a superhero movie as any other except without the superpowers. The main characters in this movie are cops that have thrown down their badges in favor of doing some vigilante justice. They are no different than Batman, a member of the Justice League, who also takes justice into his own hands. Like superheroes, they seem to always find a way to outmatch their opponents and often do so with sheer brute force. Even when not as strong as an opponent they may still win just out of their willpower alone which is much like another Justice League character, Green Lantern.
The problem is that Gangster Squad fills out all these stereotypical superhero traits in a way that ultimately is just too familiar. Every character's arc and ultimate fate can be deciphered upon their first appearances. The end of the movie can be mapped out in one's brain with ease long before it ever takes place. This is not an original film, but an homage to films of the past. So it is hard to ever really feel much of any kind of tension or real emotion as the characters all go through the checklist of things needed for this type of movie.
That said, some of the dialogue is fun and the action at times is also a thrill to watch. Particularly entertaining is Sean Penn putting himself fully into a villain role as gangster Mickey Cohen. His dialogue often made me laugh. I'm not sure if that was the intention, but a man proclaiming his love of having just one fork to choose from entertained me none the less. Also good, though cliche, is the dialogue between Ryan Gosling and Emma Stone's characters. One is a cop and the other is Mickey Cohen's current attraction. They shouldn't go near each other, but of course they do and problems and passion ensue.
The acting is probably the strong point of the movie. The actors all play their character types well. Ryan Gosling is smooth as the cop trying to woo Emma Stone's Grace Faraday. Josh Brolin's body is built on morality and determination as the head of the gangster squad, John O'Mara. Sean Penn's Mickey Cohen is erupting with anger at just about everything.
The movie in the end, while entertaining, just doesn't go anywhere all that interesting. It's also one of those movies that has a "based on a true story" title card that just makes you laugh. Sure, there were cops and gangsters and women in Los Angeles at one point in time. That's true. Everything else? Probably not so much. However, a movie need not be totally truthful to be good. A movie can be all sorts of other things that work just as well. Gangster Squad offers only entertainment that, while somewhat fun, is also very predictable and is reheated from leftovers of previous films.