I remember something about a glitch for doing that. Its been so long, I might look into it for fun. I'm on a glitch binge right now anyway :P

Yeah, you beat the game then pick the Yin Yang treasure...fight Ermac...beat him with losing one round...do a Mercy...beat him again...then DO NOT FINISH HIM, just let the fatality time run out and let him fall down. Voila~free game. I think they fixed it in revision 1.2 though.

Ahh yes, thats it, I just tested it out. After you do what Konqrr describes, it will reset back to the Choose Your Destiny screen and let you pick your level of play to play again.

I remember now that I actually got to try this one out a long while back at the boardwalk in Seaside Heights, NJ. They had a rev 1.1 machine that I played for an awfully long time. Pretty sad though, I remember I was at the machine for like 40 minutes waiting for anyone else to play but no one did :-/ MK had already died around thurr.

There's also an infinite credit glitch in revision 2(NOT 2.1) of MK3. If you hit start when Kabal and Kano hit the ground during the cast part of the credits you get a free credit.

One time I played MK3 on arcade and it gave me free play after I put a coin in. I played six times. It was weird.