While we all love horror on this site, there's no denying that each person has their own sub-genre of preference. Are you a zombie zealot or a giallo groupie? There's no clear distinction in genre, and there's no doubt many more, but pick the one from the list you like most, because "Other" sucks. There is bound to be some overlap between distinctions, but pick the sub-genre that appeals to you most. So if you like BLOODY BIRTHDAY because of the slasher elements, then go slasher, but if you like it because of all those murderous children, then go for the killer kiddies.