There's several different averages across days, weeks and months that control how much "overtime" you're allowed to work. The max is 200 hours per year though.
It obviously varies, and not everyone follows these laws, especially in (game) development, etc. As long as you the employee agrees to working over time (often uncompensated) none is going to bat an eye. The important thing is that you have a law that will back you up incase your company is trying to force you.