I hate my boyfriend's video game habits
What do you hate about it?
He spends too much time gaming and not enough time with me.
If he played games before and plays them now, you should not try to change him. He is probably set in his ways.
He knows I hate his gaming habits, but he refuses to change.
If you and your boyfriend can't see eye to eye about his gaming habit, then maybe you should consider ending the relationship. It seems like gaming is a big part of his life, and if you don't like it then you should find someone who is interested in the things that you are.