How do I keep my citizens happy?
The Coliseum is where your citizens hold their festivals and athletic events. These activities provide your citizens with excitement and entertainment, and increases their Happiness. Leveling up your Coliseum will provide a greater bonus, but your Happiness can never exceed 100. Hosting events in your Coliseum will earn you more happiness bonuses as well as other rewards for your city!
In addition, you can apply the Bacchanalia item that will instantly increase your City's population to 100. You can locate this item in the Shop or win it from Fortuna's Gamble.