Recognition of achievement (6)
(Other definitions for credit that I've seen before include "good grade" , "Belief - trust - favourable acknowledgment" , "Positive balance in account" , "Add (an amount) to an account" , "Believe, tick" .)
(Other definitions for reward that I've seen before include "Something given for achievement" , "Deserved prize" , "Prize; pay-off" , "Bounty; recompense" , "Prize payment" .)