Regardless of the laws where you live, this is solid advice for every game dev. Even if you're allowed to work on your own projects in your free time, don't disclose them to your employer. I've been fortunate to work at some studios that were supportive and encouraging, but you can never assume.
Austin KelmoreA much better way to work on side projects is to do it and not tell your company or post publicly about it. What the capitalists are doing is trying to flex their power to stop any and all competition. You're unlikely to win a direct confrontation, but you can win by ignoring them.