One gives nothing away about computer game returns (5)
I believe the answer is:
miser
'one gives nothing away' is the definition.
(someone who won't give money away)
'about computer game returns' is the wordplay.
'about' becomes 're' ('re' means regarding or about).
'computer game' becomes 'sim' (short for simulation).
'returns' says the letters should be written in reverse.
're'+'sim'='resim'
'resim' backwards is 'MISER'.
(Other definitions for miser that I've seen before include "Stingy hoarder" , "One's tight" , "not a spendthrift" , "hunks" , "Niggardly person" .)