"It is bad - but seriously, it is just a computer game... A 16 or 17 yr old is unlikely to be traumatised."
How the heck would anyone know this?
The more you see extreme violence in any form, in RL/animated or in film/games, the more normalised it becomes.
Computer games have only existed in our generation. TV/Film standards have nosedived, violence and related crime is higher, general standard of behaviour is lower.
The film/game censors are there for a reason, we simply do not know the effects of ultra violent, ultra realistic game exposure to our DC, it's 18 for a reason.
I'm sorry, but I happen to think that anyone that buys this or allows their much younger DC to buy/play this is acting negligently.