Though I've done a fair amount of work on the game on Ubuntu Linux, I've decided to move my main development to Windows 7. The short version as to why: too many "paper cuts." The slightly longer version is, there are too many frustrations to deal with that have nothing to do with developing the game and instead eat up my time screwing around trying to get basic things like video and audio working. This last one did it for me - buzzing, crackling audio in the Blender Game Engine. With a bit of googling I found out this had nothing to do with Blender but instead is a problem with the Pulse Audio ALSA plugin. I got nowhere trying to fix the problem. I don't give up easily on these things but I need to move forward on the game.
I like Linux but I need my operating system to just work, not burn up my time demanding I google constantly, comb through obscure forum posts and bug reports to get stuff working. I think one of the big problems is that DESKTOP Linux isn't stable. Fast development is good but kernel updates that sometimes come within a day of each other and break vital desktop functionality is just a tad too fast. Even Ubuntu's 6 month cycle is too much. You can't even get new software updates unless you reinstall the whole operating system! It's insanity.
I'll do my best to continue this project as cross-platform (Windows, Mac, Linux) but the bulk of my Blender Game Engine work will be happening on Windows from now on. Hopefully I will be getting a Mac in the near future so I can get the game working there as well.