So, before we even get into what the definition of what "boon-ga boon-ga" is, let's just take a look at this arcade cabinet for a moment. We have the severed, lower body of an individual barely fitting into their mom jeans. We don't know who you're the competition is, but this game wins the prize.
"Boon-ga, boon-ga" is a game Japanese school kids play with one another on the playground during recess. To play, you form two fingers like your shooting an imaginary ass laser and cram them up the closest school kid's rear end. This seems more like a sexual asssault training program than an innocent arcade game.