0 A.D. is a free, open-source, cross-platform real-time strategy (RTS) game of ancient warfare. It's a historically-based war/economy game that allows players to relive or rewrite the history of twelve ancient civilizations, from Iberia to Mauryan India, each depicted at their peak of economic growth and military prowess. Developed using Pyrogenesis, a ground-breaking new game engine custom-built to suit this project, 0 A.D. will give players a rich and entertaining real-time gaming experience.
Alpha 10 won't have working gates. However, players can be creative and create what I call "Murder Paths", which are essentially entryways through the player's wall system that no sane enemy would want to march his soldiers through. (Each one of those wall towers shoots arrows.)