In the NES version of Super Mario Bros. you can take advantage of a quirk and bounce off the back of a turtle to get lots of extra lives.

So, in an effort to to get the most out of your quarter, and possibly impress the other arcade-goers with your prowess, you work your way to the end of world 3-1 only to discover:

Your Koopas have been replaced with Goombas. And what that means is that you can't do your super-snazzy trick any more... which means that I hope that you brought lots of quarters.