OpenClonk or the original Clonk:Rage
Both are free games in which you control characters alone or in Co-Op to play a variety of different gamemodes with objectives such as base building, PVP modes, Mining, PVE, and a bunch more.
If you like the base game of either one there is a pretty large collection of mods that you can have even more fun in or just improve the game with also.
Another open source game I've been having a lot of fun with lately is OpenClonk. It's kind of like a real-time worms but with resource gathering and building construction. There is still a lot they have yet to add to the game but it's already quite enjoyable as it is.
Minecraft is a rip of Infiniminer when it got discontinued. Infiniminer since then has been recontinued: http://thesiteformerlyknownas.zachtronicsindustries.com/?p=713
Terraria is a rip of OpenClonks when it got discontinued. Openclonks since then has been recontinued: http://www.openclonk.org/
I haven't played the game, so maybe what you're posting for download is something different, but this page right here has a download that says it includes the basic game and all the addon packs and is now freeware...
http://www.clonk.de/cr.php?lng=en
There's also this opensource version of it...
Also, paging /u/buzz120 and /u/Satsuz
Eine ausgezeichnete Alternative zu Terraria ist die 21 Jahre alte Spieleserie "Clonk" mit seinem neusten Ableger von 2008 (http://www.clonk.de/cr.php?lng=de) und einer von Fans entwickelten OpenSource-Version (http://www.openclonk.org).
Beide Spiele sind (mittlerweile) kostenlos verfügbar, stark modifizierbar und mega spaßig, wenn man's mit mehreren Leuten spielt. Mich begleitet das Spiel schon seit 1995, als ich es auf einer Shareware-CD neben 100 anderen MSDOS-Demoversionen entdeckte.
Cortex Command has a linux version but I could never get it to run properly. Clonk Rage is a lot of fun though and the Hazard mod for it adds modern weapons. Openclonk is getting pretty good now too.