“Hot Tub Party Massacre” (0 stars out of four) was an absolutely worthless horror show that looks like someone’s bad home movies; some annoying sorority sisters win a free weekend at a luxurious hotel spa and are dismayed when an escaped serial killer crashes the party. But believe me- you’ll be rooting for him to put each one of them out of their (and the audience’s) misery. The kind of inept horror movie that gives the term “low-budget” a bad name. Grade Z acting and filmmaking turn this into a real massacre.