age appropriate games

My little man is into playing online games. He loves to discover new games online to play with. I allow him to play games that I know will help his thinking skills. The games also help him being nimble on his fingers when clicking keys on the keyboard. Boy, he is fast! He is only five years old so I keep an eye on what he does and where he goes online to make sure he is not doing anything he is not supposed to. He talks to his one cousin about online games (the older boy plays online too) and they compare games and technics to win games. One time his cousin asked him if he has Playstation and if he has heard of a game Assassins Creed: Revelations because he is starting to play it. The little man said no but he seemed to be interested. I told him he cannot play games like that yet though. His cousin is way older so he can play the game with his dad but the little man is still young for such games. He seems to understand but I have been asked several times already if he is grown up yet, lol. I hope he will forget about the game for now. Maybe in the future if he is still interested we might let him play especially since his cousin already has the game. It will be easier then. For now, he has to stick playing games that are more age appropriate.