Robert Rodriguez is having a bad time with trilogies. After a disappointing outing with Spy Kids 3-D, he turns in almost as disappointing a mess with the third film of his El Mariachi cycle, Once Upon A Time In Mexico. Though burdened down by an overly complex and weighty political plot, the continuing tale of Antonio Banderas as gunslinging singer Mariachi has some things going for it that make it watchable, particularly for hard-core fans. The good: Johnny Depp continues his latest streak of completely nutty characters with a chatty CIA agent with a penchant for bad disguises. Don’t be fooled by his Matrix-look on the posters; most of the time he’s the hilarious epitome of the tacky American abroad. Speaking of comedy, the sly humor is often funnier than anything in Spy Kids 3-D. The bad: The action scenes are completely gratuitous, even considering the kind of movie this is. Most of the fights exist for no other purpose than to have some bad guys show up with guns and spice up the goings-on. And the complete inability of any villains to shoot in a straight line is embarrassing even by action-film standards. Armed with automatic weapons, they can’t kill people 5 feet in front of them. If you want good action, just go back and watch the bar battle in Desperado. It’s better than anything in this movie. Banderas still has his steely cold charisma in the role, but El Mariachi never really has anyone to play off of and balance his grim demeanor, as Salma Hayek is barely in the movie despite her top billing. A couple of new sidekicks show up but never really catch on. The ugly: The mix of gritty political drama with over-the-top action never completely works in this movie. Setting up all the chess pieces and then dropping an unkillable superhero into the mix works a lot better in theory than in actual practice. Instead, it’s a long series of talky scenes scattered with random shooting, sort of like The Matrix Reloaded. Rodriguez has probably got a strong Mexican political epic in him, but this isn’t it.