How to unlock Event Match Levels 11 - 51:
Levels 11 - 15 Win 6 different matches from Levels 1-10
Levels 16 - 20 Win 10 different matches from Levels 1-15
Levels 21 - 25 Win 16 different matches from Levels 1-20
Levels 26 - 29 Win 22 different matches from Levels 1-25
Level 30 Win 27 different matches from Levels 1-29
Levels 31 - 39 Complete 30 Levels and unlock 4 specific hidden characters
Levels 40 - 50 Complete 30 Levels and unlock all hidden characters except Pichu
Level 51 Complete Levels 1-50 and defeat Giga Bowser in Adventure Mode