Up-beat game (4)
I believe the answer is:
golf
'game' is the definition.
(golf game is a kind of game)
'up-beat' is the wordplay.
'up' says the letters should be written in reverse (in down clue: letters go upwards).
'beat' becomes 'flog' (flogging is a kind of beating).
'flog' back-to-front is 'GOLF'.
(Other definitions for golf that I've seen before include "The game some say spoils a good walk" , "Outdoor game" , "Foxtrot follower" , "Game on course" , "Sport in which the Ryder Cup features" .)