There has been much debate over whether certain kids of video games can help or hurt kids' learning. I think that it depends on how much time you spend playing video games on average, as well as what kind of game you are playing (violent single shooter games, for example, as opposed to puzzle or problem-solving games). I'm not sure that video games can affect memory if you spend too much time playing them, but it's certainly not healthy to focus too much of your attention on games for too long.
Here are a few articles on the topic. I hope this answers your question!