Where can I setup expiration time? It would be cool if you can setup expiration time at start, with 0 for unlimited time too.
Open the chess.php file and find the following line:
if ( timePassed( trim($game) ) > 2419200 /*four weeks*/ )
2419200 is the amount of time in seconds - change this to what you want..
2419200 month (4 weeks)
It's not set up to set the time for each game...perhaps that feature could be added in a future release.
Hope this helps.