There's a place like that in my city, one that breaks probably all of advices listed here, and yet is extremely popular, so instead of giving advices, I guess I'll just try my best to describe it

I've found
one photo of it as well a photogallery:
The Troll:
Clicky!
To start - it's not a cafe, but rather a pub. You go in, and either to up to the gaming area on first floor, or stay on ground floor where the pub is.
All walls are painted as dungeon/ruins surrounding, it's all quite expressionistic, with trolls as focus. The tables are made of irregular, heavy wood, with benches on area on left, and big metal chairs on area on right (both are separated by stairwell, seen on photo on the right).
What's very interesting - is that they focused on gamers and their friends, and realized that gaming is not all that gamers
do. There's all kinds of great music to be heard, there are movies nights, and just the right beverages: it's the only joint around that offers the clients both Specjal (cheap beer beloved by students and construction workers), and Koźlak (local bock beer, high end). Oh, and they do offer 1 pint mugs, that has to count for something
As to the snacks - two fold plan. A lot of gamers are in high school of University, so they don't have a lot of cash, thus snacks are cheap but last for long - peanuts, that kind of jazz. On the other hand, sometimes people come there straight from school/job, so a hamburger is needed.
What you need to understand is how focused this joint is on it's clientèle. I'll give you insight from some clients from our city portal here with translation by Google:
LINKY <- note that average rating of 5.4 out of 6 was lowered by a customer that gave 2 x 1 and a 2.
Now brace for impact: the pub is hardly lit at all, it's right by railtrack (like, 3 meters from entrance), the service tends to be snarky, the music is very loud, with train intermissions, and no one figured out the bathroom lock within first 2-3 visits.
The thing is - it's The
Troll. It's supposed to be that way, and if someone knows it - you know he's an OK guy/lass. In theory, it'd be nicer if it offered high-end snacks - but hardly anyone could buy them, so why bother (in your case it'll be also choice between nachos or another mini, hmmm...)? Sure, the trains are loud, but you can leave the joint at very last minute before your
S-bahn leaves, and it's easy to find for people from other parts of tricity. The service treats new people a bit like intruders - because that's what they are - but old customers can not only chat away, but more importantly - get a tab ;-)
How far from tracks?
Not far at all.
Bottom line - it's the pub of choice for gamers because it's a place a gamer made and that gamers enjoy. The fact that there's a gaming area is just a neat bonus. They got what counts for their clients just right, and simply didn't bother at all about the rest, which is why on a 6-points scale, a posh girl wandering in by accident will end up with 2.2 impression when regulars think of it as a strong
6.
Since you don't want to get an alcohol concession (I imagine it doesn't cover that age-group so well when drinking age is 21 instead of 18

), figure out what gamers like, which might end up a tad strange, but that could work out great for the focus group (ie - hot water dispensers - I hear yerba mate is very popular in America ;-) ).
Edit: btw - my parents are in gastronomic industry, so I know this and that - don't go extra mile to get alcohol concession - it's now worth it if it's going to be bought by small part of clients, especially not if it's mostly beer - the profit margin on beer is ridiculously small, and you have to deal with all kinds of crap. You earn mostly on hard liquors, and selling under 2 kegs per evening is just a massive waste of time, whereas you get up to several hundreds % of profit on each cup of coffee/ tea.
Another - it might be profitable to buy proper tea, not the bagged scraps. Dunno about the prices in US, but the price here, mean that I can buy great tea for about the same price as tetley (per kg). For some reason, Dilmah is even costlier than any blend of much better tea bought in proper tea-shop. Same goes for coffee, but for another mile - buy
beans. It's not cutting into your profits too much, and it'll mean it's going to be the best coffee they're going to get.
Ice tea - screw Nestle, man - make your own. All tea shops have some blends precisely for iced tea - most of the time it's based on a bitter tea type like Chun Mee, lemongrass, mint, calendula and some aromas (ie peach). Note, that each batch of tea can be brewed about 3 times. 1st one is a bit too strong, and in Japan it's simply thrown away, 3rd is the weakest, and 2nd is considered the best.
What I do - is that I use 1st and 3rd brew to make iced tea, and drink hot only the 2nd. It's too much of a hassle for one person when it's not very hot (ie - summer

), but it can work out far better for a joint when it goes in larger quantities.
To keep on top of it and not have to think too much about it, you could either buy an immensely overpriced Chinese
waste baskets, or use what I do - a couple of bamboo strainers

They're piss-cheap, and while I don't like using them to actually make tea - but they're great as temporary waste baskets

I make 1st batch of tea in any vessel I like to, preferably big (a lot of tea fits into those things) and put it aside. Whenever I want to make hot tea, I take it from that basket, and afterwards - throw it into another one, that's marked. When 1st is empty and 2nd is full - I make second batch of of tea in bigger vessel, mix it with the one I made earlier and put it aside to cool down, and then make another batch with fresh leaves to start cooling down.
The thing here is, that you'll be able to make high end, poshy product - for about the same price of the low-end materials.