Bad, you guys are only posting free as in free beer games which don't respect your 4 essential freedoms. educate yourselfs https://www.gnu.org/philosophy/free-sw.html
here are some free as in freedom games which are really good and don't requre big bad spooky proprietary operating systems also in the future please specify which free you are talking about
http://www.xonotic.org/
xonotic a fps arena shooter game based off of the darkplaces engine which was based off of the quake one engine. it is really fun but unfortionately not many people actively play
http://supertuxkart.sourceforge.net/
Super tux cart
FUCK MARIO CART THIS SHIT IT THE FUTURE OF RACING GAMES
here are some free as in freedom games which are really good and don't requre big bad spooky proprietary operating systems also in the future please specify which free you are talking about
http://www.xonotic.org/
xonotic a fps arena shooter game based off of the darkplaces engine which was based off of the quake one engine. it is really fun but unfortionately not many people actively play
http://supertuxkart.sourceforge.net/
Super tux cart
FUCK MARIO CART THIS SHIT IT THE FUTURE OF RACING GAMES