I miss the single player adventure games like from Sierra and Lucas Arts where you can engross yourself in a story game line, and have work to solve puzzles and you celibate when you continue the story plot, without having to use twitch like hand eye coordination, or play online with a bunch of people just trying to mess you up.
But those times have ended. It is too easy and tempting to get spoilers on line, people tolerance towards game frustration has diminished...
Now he made a popular open source game, people liked it and it grew for a time. That is great... however times change, and popular games soon become tiresome. Updates and fixes and new content doesn't really excite as much after a while.
There isn't really that much to gain in Open Source games, because of the entertainment value of the game vs practical value. A game will offer a few months of joy perhaps a couple of years, then it will get old and tiresome, and they will be a new one out. You are better off selling it make a lot of money from it, then go on to new projects once it has peaked. I am not trying to be Mr. Anti Open Source, but Open Source works better on serious infrastructure type of projects, Operating Systems, Web Servers, Databases, programming languages... These tend to have long term demand, and invested interests on maintaining the project, including full time support. If my company is dependent on the success of an Open Source project, it may be useful, to hire resources to contribute to it, it may be a better value then buying stock into a closed source company, as you are actively contributing you get a better say on what goes on in your critical infrastructure software needs.