The nice thing about flash is that the files can be saved as an executable file that can be played without a browser. I think they are called projector files, not 100% sure. So upon boot up the computer can launch the executable automatically.
I did a couple of google searches and there a number of free video game software packages available (mostly flash based) that accept keystroke inputs, but I have not been able to figured out if they can output a keystroke.
So using an i-pac for input and a pac-drive for output.
Lets say we create a basic flash game where whenever the letter "A" is input 100 points is added to the score and a sound plays. Now I suppose you could have the pac-drive setup to blink a light or light up a playfield insert off that same letter "A" keystroke, but I am thinking we would want the flash game to create a new different keystroke signal to go out to the pac-drive.
Now the reason I would want this is to create a rule set. So for example you program the flash game that after the letter "A" has been input five times the letter "B" input which is normally only worth 100 points will now be worth 20,000 points for a limited time of 30 seconds. But to let the player know this you need the playfield insert in front of input "B" to blink. So you want to program flash that after the letter "A" has been input five times to have it create a key stroke signal equal to the letter "Q" on the keyboard that is picked up by the pac-drive board as an input to light the corresponding playfield insert.
Now the only issue is finding out if flash (or a flash based game maker) can be told to create a keystroke signal.