Rating issues
The violence is all textual. Sometimes it’s a bit dark, but it never gets to a gross/disturbing point. The older your monster gets, the more serious the missions will be. You begin with monster baby issues, easy choices, harm friends or make them happy. This gradually increases to a point where you can influence what monsters think of humans, and what humans think of monsters. Some texts/mission choices include the option to rip apart animals or kill humans. However, this content is never actually depicted.
Other issues
The game revolves around monster. However the artwork is really cheerful and funny. Some encounters could be disturbing, but it never reaches the point it would be rated as ‘fear’.