There are 3 difficulties in each level. Completing the level increases the difficulty.
Higher difficulty levels have less moves and higher requirements. Some levels require higher difficulty to make progress at a factory.
Higher score requirement, more tiles, more blockers, more souvenirs, more colors, some special changes such as arrangement of gummies.
Each level after level 20 in Sydney can be played three times with each subsequent tier becoming more challenging.
The three difficulty modes in ascending order are Intern, Architect, and Master Builder.
To complete a city and unlock the next, each level's Intern mode must be beaten once. A level's Architect and Master Builder modes can be played to earn more coins, more resources, or other rewards like purple Local Workers.
Types of difficulty
Lowest difficulty, earns 10 coins.
Medium difficulty, earns 30 coins.
Highest difficulty, earns 60 coins.