Ranked in these QuestionsQuestion Ranking
Pro One of the only free RTSes available being actively developed
When it comes to a completely free RTS that is being actively developed there are few options, or really only one, this game. So for that part, the best option available as it is really the only one. While there may be some free to play RTS options available they do rely on in game transactions where this title will have none.
Pro Free and open-source
Even if the current developer team chooses to no longer work on the game, others can keep contributing to the source code and modify it.
Pro Multi-platform support
The game will run on Linux, OSX and Windows, which is great for people who dual boot or just use multiple OS's across their devices. No matter the OS used, one can install and play this game.
Pro Straightforward RTS gameplay
0 A.D. brings familiar straightforward real time strategy gameplay for free using open source code. With a mini-map in the bottom corner, resources shown in a bar at the bottom and of course unit selection through double clicking, all of the major elements found in most RTS games is here, making for a very familiar game for those that are used to the genre.
Pro Active development
By being in active development the game allows for frequent bug fixes as well as frequent new content. While it is still in alpha, the state of the game playability is pretty good with new features being added all the time.
Pro Addictive Aoe style game that works on nearly any OS
This game is very similar to Age of Empires, so it should be right up the alley for fans of AoE as they will be familiar with the style of gameplay.
Con Currently in alpha
0 A.D. is an ongoing open source project that is as of yet feature complete.