Saved World and active game
The saved World is your authored content. Play starts an active game from it. Ordinary script changes to Cells and Actors affect that game session. Stopping Play discards temporary changes.
Temporary objects
Cells created with cell.new() and controls created with ui.new() are temporary. Deleting an authored Cell during Play does not delete it from the saved World.
Keep progress [BETA]
Use Save data for supported values that must survive a restart. Do not treat a changed World object or a Module variable as a durable save.