De-sensitised?

This is a conversation that I recently had with a young person. He was talking about the console game Call of Duty.

Me: What certificate is that?

YP: A 15

Me: Is it violent?

YP: No not really

Me: What happens in it? ISn't it about war?

YP: Yeah, but it isn't violent.

Me: What happens then?

YP: You shoot people, but you don't see much. There's no guts splurging out or anything.

Me; But they die?

YP: Yeah