Good question brother. I think this is an easy thing to answer.
Wizards = bad
2 Kings 21:6
He sacrificed his own son in the fire, practiced sorcery and divination, and consulted mediums and spiritists. He did much evil in the eyes of the LORD, provoking him to anger.
Violence = bad
Proverbs 1:10-16
10 My son, if sinners entice you,
do not give in to them.
11 If they say, "Come along with us;
let's lie in wait for someone's blood,
let's waylay some harmless soul;
12 let's swallow them alive, like the grave,
and whole, like those who go down to the pit;
13 we will get all sorts of valuable things
and fill our houses with plunder;
14 throw in your lot with us,
and we will share a common purse"-
15 my son, do not go along with them,
do not set foot on their paths;
16 for their feet rush into sin,
they are swift to shed blood.
Just picture Jesus Christ. Would He play these kind of games? I know it may look silly to imagine Christ playing video games, but you know what? Who is to say GOD does not appreciate entertainment? Look at the world and the galaxies beyond! He did it for His glory and joy.
It might be "only entertainment" but if you would not do it in real life, then its a conviction there that it is wrong to be entertained by it.
It also eats up precious time with the Lord very easily. Games are addicting to many kids and adults.