Following the riotous Kiwi horror parody "What We Do in the Shadows," New Zealand takes another slap at shock in "Deathgasm" (⋆⋆⋆ out of four stars; unrated, amazing amounts of profanity, sex and violence). Metal rock headbanger Brodie (Milo Cawthorne) and his high school bandmates try turning some ancient sheet music into raw rock power. What they didn't realize is that they were playing the greatest hits of demonic satanic hordes. Like "Spinal Tap" filled with goofy gore, it turns the darkness and anger that death metal buffs know and love into a fun, knowing travesty of terror. It won't carry fans of "Shaun of the Dead" or "Army of Darkness" into unexplored territory, but it's energetic enough to slap a stupid grin on your face. (9:45 p.m. Fri.-Sat., St. Anthony Main) COLIN COVERT