The smiley face on the bottom of the screen shows your population’s overall happiness and represents your overall Approval Rating. Click the icon to view the Approval Rating panel. The panel displays three happiness meters, separating the residents into Residential, Commercial, and Industrial categories. The more each meter is filled, the higher your rating is for that category. If your Approval Rating is low and your people are unhappy in a particular category, click on each individual meter to see more detailed comments. Address these comments and concerns to increase your Approval Rating.
SimCity: Approval Rating