Is one required to show an ID when entering, even when it's just to play around at the arcade. Also i heard they use a card system for the games here. How does that work roughly?

Cards have to formats one where you have infinite play but no tickets for getting prizes the other where you have a limited play and received tickets for prices they may have also a format where you get both infinite play on some but a limited amount of tokens that will allow you to get tickets. There is no idea check when entering at least that was my experienceThat said I did not go to the bar area nor the restaurant where it may be required. As a side note on the cards all tickets that you may win if using a card capable are registered through the system and not physical tickets.

You must be 18 or over to enter without an adult.