I think that most people will remain unmoved by things that they witness while playing a game. There are some people however, who are very susceptible to any form of medium that they come across and are very much influenced by it. I think the onus lies on the parents to teach them right from wrong.
Yes, video games have a history of being too violent and showing intimacy. When children play these video games at a young age, they start to act out what they see and hear. So, if they see someone shooting a gun, for example, then they pretend to have a gun or use a toy gun and pretend to shoot it as well. Video games these days aren't educational and are more violent than ever before.
Video games are nothing but a form of amusement. Video games are no different than television, they are just a pass time. Video games are healthy for kids as they are developing their cognitive skills, however it is the same as regular playing. This is a just a new way of playing with traditional toys.