有一些语法错误,修正如下：
My opinion is: playing computer games can make you relax,make you very happy and they also can help you a lot in many ways, such as how to answer questions , how to cook and so on . But if you are addited to them, they waste your time . Every coin has two sides(每个硬币都有两面/凡事均有两面性）, so does playing computer games. (玩电脑游戏也一样）Sometimes it is good for you, but sometimes it is bad.
你的错误主要在于：动词作主语或宾语时不记得加ing,我们知道动词原形是不能直接作主语或宾语的.
希望对你有用!