Game that's nice to play wearing crown (8)
I believe the answer is:
patience
'game' is the definition.
(I've seen this before)
'nice to play wearing crown' is the wordplay.
'to play' is an anagram indicator.
'wearing' means one lot of letters goes inside another.
'crown' becomes 'pate' ('pate' can be a synonym of 'crown'**).
'nice' with letters rearranged gives 'ienc'.
'ienc' inserted into 'pate' is 'PATIENCE'.
'that's' is the link.
(Other definitions for patience that I've seen before include "Waiting without complaint" , "Waiting calmly" , "Solo card game, played with equanimity" , "Work by G&S" , "Card game - virtue" .)