doesn't fix my problem at the moment, but thanks for that as didn't really think about it possibly not waiting for metacity
the problem seems to be between executing penumbra and replacing compiz back again; the game attempts to start, but then "compiz --replace" seems to run and stops the game from opening, it doesn't wait for penumbra to play fully until the game is quitted, I thought it would work as technically "./penumbra" will be running as long as the game is open and when closed it would then move to the next line in the script, but doesn't seem to be the case