I have experience with people that put castors on pinball machines, and the absolute answer is NO. Do not do this. Go down to Home Depot and buy a set of "sliders". They make these for multiple surfaces. For carpet, they are smooth plastic bottoms. And for hardwood, they are a fluffy carpet on the bottom. Just like PinSkates, you need to get under the machine to put them in. You just pop the game up on your back, and put them under. You can also lift the end of the game and slide it under the leg with your foot, but I highly recommend against that because it puts you into an awkward position and you might wrench your back doing it that way.

Those are cheap (less than 20 for a big set, and cheaper for single sets). The machine will slide easily. Then you just pup them out and put them in the cupboard until the next time you have to move a game.

Personally I still use sliders in one of my rooms. I own PinSkates, and I have a real pinball cart (which is worth owning with as many games as I have). Just don't use castors, because the game will not be stable, and it will be unsatisfying to play. Even when they feel like they lock in, over time playing them they will shift, and you might slam the heads of games into each other. Also, don't leave sliders under games, for the same reason.