Raze is a fresh attempt to bring together many different games under one roof including Duke Nukem 3D, Blood, Redneck Rampage, Shadow Warrior and Exhumed/Powerslave.
DevilutionX aims to make playing the classic Diablo and Hellfire on modern systems a breeze, with a full public domain coded reimplementation and a big new 1.2 version is out now.
Want to jump in and see how another game is made? Now is another chance! The koi breeding game Koi Farm that released on Steam on February 26 has now released the source code.
Another promising game engine with lots of big features is Flax, available free with the source available (but not Open Source) has a huge new release out with improvements to their Linux support.
Want to revisit the classic GTA III and Vice City? You should take a look at re3 and reVC which not only provide the source code, they also upgrade the experience for both.
Defold, a free game engine with the source code available under a reasonable open license has released a roadmap for 2021 and it's sounding pretty good.
Looking to make games? Defold is a pretty great option that has wonderful cross-platform support and it's free too, available under a pretty open license (but not open source).
FreeSpace and FreeSpace 2 are two of the absolute best space shooters around, and thankfully FreeSpace 2 continues living on very nicely with the FreeSpace 2 Source Code Project. A new release is up after another year of work.
A lot of game developer still worry about being more open with their code but it seems Terry Cavanagh (VVVVVV, Super Hexagon, Dicey Dungeons) believes it was worth it.
Diablo is something of a classic and it lives on thanks to the public domain game engine DevilutionX.
Something for the weekend perhaps, as the excellent first-person dungeon crawler Delver has been released DRM-free on the indie game store itch.io.
The community working to keep the classic Jagged Alliance 2 alive with the Stracciatella game engine have put out their first release in a few years.
The Defold Foundation recently announced another partnership, as they've secured a grant from Grant for the Web to bring in support for the Web Monetization API.
Recently, game developer King transferred the source code for the Defold game engine over to a new Defold Foundation where they opened up the source and now they have a new sponsor.
Cross-platform game engine Defold has announced that the source code is now available under a reasonably generous license, along with the formation of a Defold Foundation.
A wonderful little programming-puzzle game here with Selfless Heroes, tasking you with helping heroes travel through a dungeon and avoid dangers.
Anodyne, a Zelda-lite action adventure from Analgesic Productions from back in 2013 has today had the code opened up.
VVVVVV, the clever platformer from Terry Cavanagh where you reverse gravity instead of jumping has now had the source code opened up so you can see the dirty innards.