9. Life Is Strange
Life is Strange is an episodic adventure game about Maxine, a young girl who discovers that she can rewind time. One of the mysteries of the game concerns a string of murders, the victims of which are other girls her age. Eventually it is revealed that the killer is her photography teacher Mr. Jefferson
An explicit hint to this truth is presented right at the start of the first episode, and it comes straight from Mr. Jefferson himself. As he is lecturing his students, he begins talking about how photography can be used to capture moments of desperation in people, all the while only looking at the female students. What on the surface appears to be a simple tangent in an average lecture is him literally explaining his MO to his students, who are blissfully unaware about the horrible truth behind his words.
Diligent gamers probably figured out his identity early on. In fact, Mr. Jefferson even says as much, telling Max (and the player) that, had she listened to him in class, she would have seen it coming. The game lays it all out there right from the start; you only have to pay attention to figure it out.