Ashley Tisdale is leaving "High School Musical" behind to fend off aliens in her new flick, "They Came from Upstairs." But Tisdale promises that this alien movie is part comedy too.

"I think it's funny," she told MTV News about the flick, which opens July 31. "If you saw them you'd think they were funny."

Not only does she get a chance to use her comedic skills in the film, but Tisdale also gets a chance to embrace her inner action hero. "I had this whole action scene," she explained. "It was all CGI. I had all this choreography. I'm sure it's going to come out really cool."

Before she has to fight the aliens, it takes her character, Bethany, awhile to figure out just what is going on. "So I don't know what's going on and I'm kind of like the bitchy sister," Tisdale said. "I'm not really nice. ... You don't really like me in the beginning, 'cause I'm so in love with this guy [played by Robert Hoffman]."

Much like with the aliens, Tisdale doesn't fully understand just what Bethany is getting to with Robert's character, Ricky. "Robert's [character is] actually the guy who is like the ['Leave It to Beaver' wise guy] Eddie Haskell, so he's like really nice to me and my mom and dad and then to my brother he's horrible, so you start to see his true colors."

Check out everything we've got on "They Came From Upstairs."

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