there are many nice free games on
http://www.newbreedsoftware.com/windows/
you can see especially
http://supertux.berlios.de/wiki/index.php/Download/Installation#Windows_Installer
which is a super mario cloned game you install the game and enjoy!
these games are (or most are) open source
you can find more on
http://directory.fsf.org/games/
if even you are developper you can participate on developping open source games
You can also support then by making donation
http://www.newbreedsoftware.com/windows/
you can see especially
http://supertux.berlios.de/wiki/index.php/Download/Installation#Windows_Installer
which is a super mario cloned game you install the game and enjoy!
these games are (or most are) open source
you can find more on
http://directory.fsf.org/games/
if even you are developper you can participate on developping open source games
You can also support then by making donation
