The most common and most likely answer to this crossword clue is the 5 letter word SHOVE
I've seen this crossword clue in The Daily Telegraph
S
H
O
V
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 = shove.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 SHOVE mean?
SHOVE noun- A rough push.
- An all-in bet.
- A forward movement of packed river-ice.
- To push, especially roughly or with force.
- To move off or along by an act of pushing, as with an oar or pole used in a boat; sometimes with off.
- (by ellipsis) To make an all-in bet.
- To pass (counterfeit money).