"8BitMMO is a retro-style 2D massively multiplayer game! It's a giant construction sandbox -- you can build a home or a castle in a persistent streaming world. Found and manage your own city. Fight evil LawyerCats and engage in Player vs Player battle."
The games features allow you to build and manage your own town/city, be the mayor, invite your friends, customize your character and more.
Mac OS X 10.9.2 Mavericks or newer
Free download at steampowered.com