Complex sentence: The utility allowed to edit level layouts and save them as standalone games, which lead to a large number of different "Robbo" games being created on the Atari by enthusiasts, with new versions still surfacing.
Split into simpler sentences: The utility allowed to edit level layouts and save them as standalone games. This lead to a large number of different "Robbo" games being created on the Atari by enthusiasts, with new versions still surfacing.