The idea of a professional assassin who uses only poison because blood makes him projectile vomit is mildly funny. The intentionally godawful song over the end credits is almost mildly funny. Neither warranted a laugh, nor did anything else solicit one. Some people allegedly found this movie funny, but it's anyone's guess as to why - they themselves didn't specify.
Review of Killing Gunther
Killing Gunther
(2017)
under 100 reviews in two years; a deservedly little-seen movie
31 October 2019