This is remarkable because Twitter has been in the money-making game for only three years, primarily selling "sponsored tweets" to advertisers whose come-ons pop up in the message streams of the service's 200 million-plus active users.
As a result, from a game design standpoint, the general consensus among the video gaming community is that it is acceptable to include violence, even very graphic violence, in a video game for no other reason than making the game more exciting.