Great sort of game (4)
I believe the answer is:
mega
'great' is the definition.
(I've seen this in other clues)
'sort of game' is the wordplay.
'sort of' is an anagram indicator.
'game' is an anagram of 'MEGA'.
(Other definitions for mega that I've seen before include "Enormous; very good" , "As brilliant" , "wicked" , "Great American" , "Great - denoting a million" .)