Here are factors I believe will affect the rating:
- Blood (We all know there's going to be some)
- Gore (Based on a tester's statement, it could be even gorey)
- Violence ( Really?)
- Online material not Rated (Chat, private messaging, etc)

STS never had any cussing in the games they make so I don't think that it will appear in this game. I really hope so. All in all, we will see.