Shoot-EM-UP is a term used to describe a genre of films and video games that involve a lot of shooting and action. OATER, WESTERN, HORSEOPERA, and GANGSTERMOVIE are all crossword solutions for the term SHOOT-EM-UP. OATER is an acronym for 'oceanic atmospheric and terrestrial environment recorder' and is also used to refer to a type of WESTERN film. WESTERN is a genre of film set in the American Old West that typically features cowboys and outlaws. HORSEOPERA is a portmanteau of 'HORSE' and 'OPERA' and is used to describe a type of WESTERN film that focuses on HORSE riding and stunts. GANGSTERMOVIE is a type of film that focuses on organized crime and gangsters.