You have to complete all the Test Your Might challenges without fail on the way up the ladder.
This appears to be incorrect as I failed the last two Test Your Might Challenges and the Achievement unlocked for me. I did have to continue several times at Goro (and ironically I then beat him with a Double Flawless earning that Achievement), so perhaps
if you continue it doesn't count the Test Your Might successes/failures, or perhaps the Achievement is just glitched and it's random.
Myself I wont be purchasing this. I was counting down the days until this came out. But they did a awful job of emulating this and these are far from arcade perfect. Input lag in single player alone was enough to turn me off. Look it up on various MK sites
and you get a laundry list of problems. Its disgusting what a bad job they did.