Computer game Place Exodus allowing going only one way (7)
I believe the answer is:
simplex
'going only one way' is the definition.
Both the answer and definition are adjectives. Maybe you can see an association between them that I don't see?
'computer game place exodus' is the wordplay.
'computer game' becomes 'sim' (short for simulation).
'place' becomes 'pl' (abbreviation used in postal addresses).
'exodus' becomes 'ex' (I am not sure about this - if you are sure you should believe this answer much more).
'sim'+'pl'+'ex'='SIMPLEX'
'allowing' acts as a link.
Can you help me to learn more?
(Another definition for simplex that I've seen is " Your crossword".)