“Happy Birthday” (** out of four) was a curiously glum and flat horror thriller about a young woman (Maddie Henderson) whose friends (Angel Pean, Kim Sandwich, and others) take her to a haunted house for her birthday present but there is (yawn) an escaped killer on the loose. Yet another throwback to ‘80’s horror movies but duds like these were a lot more fun back then and done with more flair and conviction. Henderson’s sincere performance helps keep this on track, at least for a little while. No relation to any of the “Happy Death Day” movies.