What precautions should I take to make it so my son does not become a games addict as he grows. I know what I have lost playing games for so many years when I was young.

My 4+ year old son (will be 5 in two months) loves to play video games. I am a games addict myself - though casually. I have continued to play games on my mobile, PC and Xbox (mostly on PC). My son inherited this from me and seems like he is little addicted to it because he wants to play games almost all time.

Mostly he plays car games both in my mobile and pc (he loves cars, we buy a new car/toy almost every month) and he asks me to play other games like angry birds, batman, plants vs zombies etc.

I consider it a good thing it is all under control so far. Most of the time when we say "no, this is not the time to play" he listens to us and says "we will play again in the evening or next day morning". He gets mad if we won't allow him to play a few requests in a row. This happens when I am busy with work, my computer or my mobile. I am concerned things will worsen.

Update:

When he plays on the PC, I restrict him to play around 20 minutes but he asks me to play other games which can't play. It is the mobile on which he wants to play the whole day. It is not just my phone but he cries to play on my wife's, nephew's and my sister's phones as well. According to my wife and sister he plays more than an hour every day on someone's mobile.