After releasing Unity 2019.1 back in April, it was mentioned that the Unity Editor for Linux was moving on from experimental status and now it's very much official.
Based on the EDuke32 game engine, NBlood is a new open source port of the classic FPS Blood. From what Voidpoint (Ion Maiden) said on Twitter, it's using their version of the game engine too.
OpenMW, the excellent open source game engine for Morrowind has made some interesting progress towards supporting later games like Oblivion, Skyrim, Fallout 3 and New Vegas.
The people over at Unity have put out the first beta for the first major release of the year and there's tons of new and improved bits for game devs and Linux gamers.