Tricky choice before crucial game (3,6)
I believe the answer is:
ice hockey
'game' is the definition.
(ice hockey is a kind of game)
'tricky choice before crucial' is the wordplay.
'tricky' indicates anagramming the letters.
'before' says to put letters next to each other.
'crucial' becomes 'key' (I've seen this before).
'choice' is an anagram of 'icehoc'.
'icehoc'+'key'='ICE-HOCKEY'
(Other definitions for ice hockey that I've seen before include "Violent sport, big in North America" , "Team game played with long sticks" , "Game played by skaters with a puck" , "Sport with puck" .)