Attractive grassy areas used in first half of game (8)
I believe the answer is:
pleasing
'attractive' is the definition.
(associated in meaning)
'used in first half of game' is the wordplay.
'used in first' becomes 'plea' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'half of' means to take half the letters.
'game' becomes 'guessing' (guessing game is a kind of game).
'guessing' with half the letters taken is 'sing'.
'plea'+'sing'='PLEASING'
'grassy areas' acts as a link.
This may not be right. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for pleasing that I've seen before include "Pleasurable; satisfying" , "Gratifying" , "Delightful" , "Satisfying or appealing" , "agreeable - with 13d" .)