Constant panty shots, bouncing breasts and dubious camera angles are hallmarks of an Ecchi title. These titles are usually sexualized and designed to titillate, depicting perverted themes and focusing heavily on the female body. Nosebleeds, suspicious hand positions, faceplanting into bosoms, expressive and exaggerated body parts and other tropes characterize this genre.
A harem includes three or more characters who potentially show romantic interest in a male protagonist. The sex, gender, or orientation of the harem members is irrelevant as long as they exclusively, or at least primarily, are vying for the affections of the same individual - who may or may not reciprocate towards one, several, or none of these romantic rivals.
Horror anime create an atmosphere of unease. Like a Mystery, they encourage viewers to learn more about their world... but there may secrets that are better left unexplored. Through eerie music and sounds, visceral or disturbing imagery, or startling moments, works of Horror make you worry about what gruesome thing is coming next.