There is no good and evil. There are only normal and deviant behaviors.
The goal in my opinion shouldn't be to label behaviors good or evil but to create environments which provide the right incentives for good behaviors to emerge rather than evil. Remember "good" is just normal and "evil" is just deviant. Behavioral normalization is what most people recognize as promotion of "good behavior".
Some of us have genes which if we are put in certain environments then the behaviors from our behavioral spectrum or palette emerge at different probabilities according to these genes. By luck or fate we are placed in initial environments and if we survive these environments then we might get the chance to choose environments due to understanding of what we are capable of. Young people are often not given much of a chance at life, born into bad environments, with a set of genes which allow for some of the deviant behavior to emerge. The deviant behavior is more likely to emerge in the environments which reward or promote or provoke those kinds of behaviors.
I don't think censoring games or content has much of an impact. It might or might not be true that content desensitizes but I don't think visceral reaction is a substitute for morality or for self control. We can of course debate and discuss that but I will agree that not everyone needs to be in every kind of environment. If a certain environment is not for you because you know it will bring out the worse in you then it's best to do what you can to avoid that environment.