x skips a turn! Sorry that's not listed anywhere.
What do you think the value is for revisiting levels?
Strange, i tried some keys and X too, but it's give no result.
About revisiting:
1) grab leaved resources
2) just view as synthetic restriction.
But after some thinking, i understand ,you don't save levels after player leaves, and make revisiting may be too expensive for not too important detail. (I try to write games too, and my obsession level what live without player :P )