The requirements for this particular trophy aren't overly clear. I unlocked this trophy upon completing level 25, and the odds of being better than average when compared to humans 25 times in a row is quite low, so it probably has something to do with the medals.
On one of the levels, I only managed silver all the way across. On one level, I got a bronze. If you consider "Bronze" to be a "C" rank, then it is possible that a player merely need to get better than a Bronze average for that level to count. If anybody has NOT gotten it by level 25, an overview of what kind of medals you got could be helpful in nailing down exactly what "average" is.
With that said, since there are 50 levels, as long as you finish the game, odds are that you'll unlock this. If not, you'll certainly have to unlock it on the way to getting the "FuturLab Certified" trophy.