Take a trio of Hollywood's hottest stars — Ryan Gosling, Emma Stone, and Josh Brolin — add a heavy dose of a scene-chewing Sean Penn, and pepper in some fedoras and Tommy guns, and you get the explosive trailer for the upcoming period mob thriller Gangster Squad. (Watch the video below.) The film follows a band of corrupt LAPD cops trying to bring down 1940s mob boss Mickey Cohen, played by Penn. While Gangster Squad has no official release date yet, it's expected to hit theaters later this year. Here, five things critics are buzzing about:

1. It looks like gun-blazing fun
Director Ruben Fleischer, behind the surprise horror-comedy hit Zombieland, looks set to bring that "down-the-middle popcorn sensibility" to Gangster Squad, says Drew McWeeny at HitFix. Judging from the trailer, the movie is "far more focused on the fun than on the hunt for awards," and looks to be a "bad-ass action thriller" in which every role has been perfectly cast.  Clearly, this is a "movie that loves movies," says Kevin P. Sullivan at MTV: Classic L.A. film noir — with violence! 

2. A Jay-Z song is shrewdly employed
The use of Jay-Z's "Oh My God" in the tail end of the trailer is a surprising choice, since the song was recorded more than a half century after the events in the movie, says Forrest Wickman at Slate. And yet, it somehow matches the visuals and tone of the trailer perfectly. It's a smart strategy, says Edward Davis at Indie Wire. The song alone may sell the movie to "millennials who don't like 'old-timey' films." 

3. Is the all-star cast too large?
Fleischer has assembled an impressive cast, with Nick Nolte, Anthony Mackie, Giovanni Ribisi, and The Killing's Mireille Enos joining the aforementioned stars. But the biggest attraction is "hall-of-fame overactor Sean Penn" in a role that couldn't be more perfectly suited to his glorious scene-chewing tendencies, says Wickman. The question, says Michael Arbeiter at Hollywood, is whether the individual members of the sprawling cast will get enough material — otherwise they'll be limited to "stone-faced exposition, half-assed suave-itude, and gravel-voicery." 

4. Hey girl, it's Ryan Gosling
Gosling has a strange, unplaceable accent that only works for some roles, says Amos Barshad at Grantland. Pass: Blue Valentine, Drive. Fail: Ides of March. In this new film, Gosling is a rebel police officer putting the moves on Emma Stone, and the part "fits the accent like a glove." This is the second (presumably steamy) collaboration between Gosling and Stone, after Crazy Stupid Love, which begs the question, says Linda Sharps at The Stir: Does Stone have a "must include at least one (1) scene of me making out with Ryan Gosling" clause in her contract? 

5. The trailer's meta scene is awesome
The trailer climaxes with a crazy meta sequence in which Tommy Gun-toting mobsters tear their way through a movie screen with a stream of bullets, shooting at the audience, says Kyle Buchanan at New York. "Who needs 3D when you've got that?"