Here's a sentiment that really needs to go die in a fire. Security isn't something you win or lose at, don't treat it like it's a game. Cybercrime is CRIME. Nobody talks about regular criminals "winning", and it's not because criminals aren't getting away with stuff (they certainly are), but rather because that's a ridiculously simplistic way of looking at the world.
Defenses will always have weaknesses. There will always be victims. Stop putting all your eggs in the prevention basket and start learning how to recover from failure. Being able to recover from failure is the only way anyone succeeds.
Can you think of any GOOD reason why playing some arbitrary game on a point of sale terminal should even be possible? Why does the device have that capability? It may be cheaper to build out of mass produced computer equipment capable of doing anything than specially built electronics that can only do limited things, but if cost is the reason then we're basically just whoring out the security of our data for the price of those cost savings.