Put the pins in a back room that has swinging double doors and is technically still open to the front half of the place. Make sure the doors are nice glass-insert style wood doors in keeping with the theme of the coffeehouse vibe. It'll block the noise, but not the lights and palpable excitement going on in there. The separate room can't be set too out of the way, either. It needs to feel like "the something else that's going on there", the other half of what the place is about in order to draw folks in there.

Most importantly, you need to establish some sort of "regularity of visitation" for the pins. Whether that means some sort of weekly or monthly high score competition where the patrons who participate tweet or Instagram their high scores with the name of your store hashtagged in their post to be eligible to win some kind of store-branded prize(personalized store mug, free coffee for a week, etc.), or simply hosting a pinball league night or even starting a new league that meets just at your place for regular meetings/competitions, there are many ways of injecting some form of "previously unknown need to be at your place often", and most are quite simple.

If it's not obvious, I've thought about this a lot for myself. I can really see myself doing something similar. I just don't have the upfront cash to open an entire storefront. I've since thought about partnering up with a great local coffee shop that isn't too pretentious and actually doesn't get that many hipsters in it. It actually gets a lot of families in it for a coffee shop. I'm just waiting for the business next to them to move out and suggest a new "expansion", as it were.