The more I think about it, the open-source model doesn't really work for video games. Now, I'm not talking about releasing the code (w/o assets) under a FOSS license. I'm talking about developing the game as a community project. It just doesn't work for certain games, namely ones with a story, world, etc. What's the point if those are all public information before the game is released, and anyone is free to contribute to it, potentially ruining your original vision (assuming the non-code part of the game is also part of the community project)? I guess that's why most of the games that have been FOSS day 1 are either multiplayer games, simulation games, or strategy games.
This is especially bad if you view games as an art form that allows the creator to express himself/herself. It's better to work alone or work with a limited number of people who understand your vision. A lot of people are judgemental when it comes to script writing (just talk to anyone who worked with actors) and naturally people will bring their inner activists and demand that they change the direction to fit your views. You should stick to YOUR vision and not cater to some mob on the Internet.
Again, I'm not against people releasing games under a FOSS license. I'm also not against people making forks and under their vision, as long as the original version still exists. I think it's a good idea to just release your code when your game releases and not have it be a community project that everyone can contribute to before release. The "community project" around your game should be built around bug-fixes and porting to other platforms.