For instance the essence of a game like Pac Man could be described as "collect dots and avoid ghosts." Once you have the essence, you write your game around that, which in turn generates the remainder of the features that support it.
The game's essence is inextricably linked to each part of development so that every aspect of the project melds into one. The project manager's role is to continually ensure that the game is on track and to ensure everything supports it, and continually redirect the team toward the goal as the project moves forward. When the team internalizes this behavior, the project begins to take on a life of its own. Your job, as a project manager, is to ensure that their creativity is allowed to flourish as long as deadlines are met.
Additional features in Pac Man that support "collect dots and avoid ghosts":
- Eating Power Pellets that allow you to eat ghosts
- Earn additional points for eating multiple ghosts in a row
- Enjoy mini-cut scenes that bring out the character of the ghosts
- Collect special items at certain times