Each time you edit and save the source code of one of your games, a new revision of the source code is created.
When you publish a game, it is the latest revision that get published.
If you continue to edit the source code of the game, the published version of the game will not be affected by the edits. The published version will be the same as it where when you published the game.
When a visitor clicks play on a game. It is the latest published version that the visitor will get to play.
When an author clicks Play latest revision for a game. It is the latest revision that the author will play.
Visitors other than the author will only be able to play published versions of a game.