Alexa Vega in Machete Kills.

Robert Rodriguez brings back Danny Trejo for another round of violent B-movie action—and the joke has grown tired.

I was a big fan of the 2010 original (and the fake Grindhouse trailer), but Machete Kills gets dumb to the point of annoyance. Trejo, 69, is starting to look a little tired in the title role.

Charlie Sheen (billed under his real name, Carlos Estevez) is actually pretty funny as the president of the United States, but he only has a few scenes. The same can’t be said for Mel Gibson, who mugs his way through a bad-guy role in a manner that reveals how desperate he is to be taken seriously again. Props go to Amber Heard, who gets the film’s best part as a beauty queen/secret agent—but Sofia Vergara annoys as she screams her way through her role as a villain with machine-gun breasts, a direct, gimmicky rip-off of the girl with machine-gun legs from Rodriguez’s Planet Terror.

Rodriguez seems to be losing it to some degree—and that’s a shame.

Machete Kills is playing at theaters across the valley.