Rating issues
The main characters fight against a number of fantastical enemies, including skeletons, walking tombstones and vegetables. When enemies are hit, they flinch or recoil. When defeated, they disappear in a puff of smoke. When the main characters are hit, they flash and their health bars are reduced. When defeated, they simply disappear and respawn. There are no realistic reactions or visible injuries.
Other issues
Some aspects of the game may be slightly sinister, such as sight of floating eyeballs in a pot of soup and a level set in a graveyard, but any scary content is usually comic in nature and never very threatening.