Dirty deeds, done dirt cheap. The old AC/DC lyrics apply to some of the early films kicking off this year’s Sundance Film Festival. The annual indie-movie showcase started Thursday night, and for a handful of lucky festivalgoers, it was a wicked one.

At the tiny Egyptian Theater on Main Street, the festival kicked off with the twisted black comedy The Guard, starring Brendan Gleeson as a gun- and drug-stealing, prostitute-patronizing, racist smart-aleck Irish cop. With a hero like that, who needs a big budget? Writer-director John Michael McDonagh introduced it as “a very black comedy — with some sadness, so hopefully there’s something there for everybody.”

Gleeson got involved in the project after McDonagh’s brother, playwright Martin McDonagh, who made In Bruges (another Sundance opener from three years ago) with the actor, handed him the script. He said there was no way to resist such a colorful character, though he wondered at the post-screening Q&A whether the cops in his homeland would love it or loathe it. “I’ll let you know the next time I get a ticket for everything, or for absolutely nothing,” Gleeson joked. “I have no idea at this point. I’m going to drive very slowly.”

Later, another ultra-low-budget movie went even darker. The creepy abandoned-home thriller Silent House playing a special midnight screening for festival volunteers (though the house was also packed with studio scouts trying to gauge whether the horror film could be another Paranormal Activity). It’s a remake of a 2010 Uruguayan film, La Casa Muda — this one from veteran Sundance filmmakers Chris Kentis and Laura Lau (Open Water), and stars newcomer Elizabeth Olsen (who has famous twin sisters who share the surname). Lau’s opening remarks are certain to have moviegoers debating: “It’s been a fantastic challenge making this film, shooting in one take …” But what does “one take” mean?

That was the question audience members were arguing afterward. The story is certainly told in real-time, unfolding over the course of 86 minutes as bizarre, violent forces besiege Olsen in her family’s dilapidated lake house. But do the filmmakers ever actually cut the scene? It seems unlikely that the movie was shot in one continuous 86-minute burst, but there is also no obvious cheating (no conveniently placed poles to provide an easy wipe between two separate shots).

Lau and Kentis weren’t around at the end of the screening, perhaps unwilling to reveal their magic trick just yet.

What can’t be argued: all through the film, those seasoned industry execs were screaming and jumping like kids at a sleepover.