As a kid, I've owned games like Gears of War/ Halo, and they didn't really have any negative influence on me at that time (sure, I was pretending to chainsaw my friends and stuff with my hands, but those are things like that are what kids do, such as tag.). I still knew what was more important, mainly my studies. But I guess it depends more on the kid, and also the parent. To silent's comment, my parents have never allowed me to get a knife AT ALL, and only recently have a recieved a wooden switchblade (lol)
So yeah, it depends on the kid but also the kid's parents and whomever he hangs around with.