The most common and most likely answer to this crossword clue is the 13 letter word TICK-TACK-TOE
T
I
C
K
-
T
A
C
K
-
T
O
E
Buddy explains!
The straight part
We know that "game" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case game = tick-tack-toe.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does TICK-TACK-TOE mean?
TICK-TACK-TOE noun- (games) A game in which two players take turns putting circles and crosses on a 3x3 grid and try to get three of the same symbols in a line