Megacity is described as 'The game sees the player aim to construct a city and maintain it'. There are four games similar to Megacity for a variety of platforms, including Windows, Mac, iPhone, Linux and Android. The best alternative is SimCity. It's not free, so if you're looking for a free alternative, you could try Citybound or GoCity.
SimCity is a series of city-building simulation games, where you are given the task of founding and developing a city, while maintaining the happiness of the citizens and keeping a stable budget. Represent entire series of SimCity games.
GoCity is a groundbreaking new location-based game that lets you build your own city on the map. You can buy real-world roads and grow your city along them. Explore the game world and expand your city to new areas by moving around in the real world.
The game (developed by Monte Cristo and originally released on October 2009) offers challenging gameplay about money and space management as well as urban planning. It provides a variety of planning tools and a unicque setup for zoning.