http://www.openclonk.org/

http://www.clonk.de/classics.php?lng=en

im not really sure what this game is, and i just started playing it but it seems a little bit like a 2d minedcraft from the 90s....but whatever i think it has online multiplayer so yeah


this game looks wicked nice and is fun:
http://gritgames.wordpress.com/games/pylo-nouveau/