Take on the 7 skill/ brain tests to get an overall score, tests are based on speed, reactions, perception, coordination, memory and accuracy.
Based on the resullts so far anything over 70% is good, 80% is great and 90% is totally awesome.
Note: To get the Mega Brain medal you must get a 90% or higher average score in the normal mode of the game. A 90% average or higher playing 'single events' will not get you the medal. This makes it more of a challenge! You have to get 90% or more in one go.