Probably the best thing about American Assassin is how simple it is.

The film opens on the beach, with Mitch Rapp (Dylan O’Brien) asking his girlfriend to marry him.  No sooner has she accepted than suddenly, terrorists are washing up on the beach and, in a genuinely frightening scene, shooting everyone that they see.  Mitch is wounded.  His girlfriend is killed.

Mitch seeks revenge against the man who killed his “future wife” (to borrow a phrase from The Room) but U.S. Special Forces kill the terrorist seconds before Mitch gets the chance.  However, the CIA is so impressed, by Mitch’s single-minded and obsessive desire for revenge, that they recruit him to join Orion, a black ops unit.  Under the guidance of grizzled veteran, Stan Hurley (Michael Keaton), Mitch becomes an American assassin.  His first mission?  To stop a renegade mercenary known as the Ghost (Taylor Kitsch).

In many ways, American Assassin feels like a throwback to the action films of the early aughts.  There’s none of the moral ambiguity of the Bourne films and Mitch Rapp never indulges in any of the self-loathing that’s marred the Daniel Craig James Bond films.  Remember how Bond got drunk and tried to interrogate that rat in SPECTRE?  Judging from American Assassin, that’s something Mitch Rapp would never do.  And, if he ever did, Stan Hurley would probably tell him to stop whining and get back to work.

In American Assassin, the bad guys are undoubtedly the bad guys and the good guys are undoubtedly the good guys and, while that may not be the approach that leads to Academy Awards and overwhelming critical acclaim, it still makes for an undeniably entertaining movie.  Director Michael Cuesta does a good job with the action scenes and he gets good performances from the entire cast.  Taylor Kitsch is far more compelling as a villain than he ever was in any of his heroic roles and, not surprisingly, Michael Keaton steals the whole show as the tough but caring Stan Hurley.  Michael Keaton is definitely one of the best actors working today.  He can slide seamlessly from a prestige drama like Spotlight to an action film like American Assassin to a comic book film like Spider-Man: Homecoming and he can do it without missing a beat.  Those are three very different films and Keaton was the best thing in all of them.

And, finally, we have Dylan O’Brien.  Last year, as we all know, O’Brien was seriously injured while filming the third Maze Runner film.  At the time, it was announced that O’Brien’s injuries were “substantial but not life threatening” but I know there was a feeling that his career might be over.  Even though American Assassin was not his first film since getting injured, it was his first starring role and I have to admit that it was good to see O’Brien back and looking good.  O’Brien brought a lot of gravity to the role of Mitch Rapp.  He had the haunted look of a man obsessed with revenge.  When I saw O’Brien in The Maze Runner and, before that, in Teen Wolf, I thought he was a pleasant young actor but, in American Assassin, he gives his most mature performance to date.  With American Assassin, Dylan O’Brien grows up.

As I said, American Assassin is a simple film.  There’s not much going on beneath the surface and it you’re looking for anything deeper than pure entertainment, you might want to look elsewhere.  American Assassin is what it is and makes no apologies.  What it does, it does well.