End of game is puzzling (6)
I believe the answer is:
stumps
'end' is the definition.
(I have seen 'End of play' mean 'stumps' so perhaps 'end' could also mean 'stumps')
'game is puzzling' is the wordplay.
I cannot really understand how this works, but
'game' could be 'p' (I have seen 'French game ' mean 'p' so perhaps 'game' could also mean 'p') and 'p' is present in the answer.
The remaining letters 'stums' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
'of' is the link.
Can you help me to learn more?
(Other definitions for stumps that I've seen before include "The upright sticks in cricket wicket" , "Bowler's targets" , "Cricket posts" , "causes puzzlement" , "causes confusion" .)