They strengthened the "fun" aspects and fixed or removed the unenjoyable ones, a process Sid Meier called "surrounding the fun". After the revision, they played it again, repeating the cycle of revision and play. Playing the game repeatedly and in-depth was a rule at Firaxis.
To enhance enjoyment, they improved what was enjoyable and fixed or removed what wasn't. This process, as described by Sid Meier, is called "surrounding the fun." After making changes, they played the game again, repeating this cycle of revision and play.  Playing the game thoroughly was a rule at Firaxis.