Here's a fun one, Lord of Dwarves from developer Stellar Sage Games is a game about helping a kingdom of dwarves survive, build, and prosper. It's made on Linux too and releasing in Early Access in March.

The developer emailed in about it and to let everyone know that it was "developed in Linux using only open source software". You can actually see them showing it off on Ubuntu in a recent video.

While it's going to be in Early Access, they told me it's "feature complete with a full campaign and sandbox mode" with the extra time being used for feedback and to polish it as much as possible.

Features:

Fully constructible/destructible 3D block world

Full Campaign and tutorial

Extremely customizable Sandbox mode

Fresh game play objectives like "build a stone tower 8 blocks tall" or "chop down an evil forest"

Control over 100 dwarves

Invaders siege your custom built structures

Tiered resource system allows for ever more powerful weapons, armour, & crafts

Random procedurally generated terrain with millions of blocks

Follow it along and wishlist on Steam. It should be available on March 8th, I will take a look and give it some thoughts at release as the developer has already kindly provided a key for testing.