Developer HEY and Japanese publisher Hanaji Games have released Dezatopia, an imaginative and unique feeling multi-directional shoot 'em up with Linux support.
I grew up playing the early Sonic games so Open Surge really speaks to me. A retro Sonic-inspired platformer (that's actually quite polished already) and a game engine for others to create with it.
A lot of the time Kickstarter (and other crowdfunding) for indie games goes well, in fact the vast majority of the time all is fine. Sometimes though, everything breaks down as is the case with Drift Stage.
A retro inspired fantasy RPG with a focus on strategic action? With a story? Fates of Ort looks and sounds like it's going to be very interesting to play.
Now this is some classic gaming. Cannon Fodder is a game I remember playing on the Amiga and it's being kept alive with a cross-platform open source game engine called Open Fodder.
A Date in the Park is a lightweight point and click adventure that will take you approximately one hour to solve. It was actually released more than five years ago, but thanks to Proton 4.11, it is now possible to enjoy it on Linux -almost- without any problems.
Thanks to the awesome power of DOSBox, even more classics are now available on GOG with Linux bundled builds available for your holiday retro gaming needs.
Developed Namo Gamo recently released their retro-inspired sports game Basketball Classics, what they say "bridges the gap between retro and today’s simulation games".
Starting off with a successful crowdfunding campaign back in 2013 has grown into a massive multi-part 8-bit inspired world with Shovel Knight: Treasure Trove now finally finished.
Kharon's Crypt - Even Death May Die, a nonlinear dungeon crawler inspired by old Nintendo Game Boy Color games and Zelda is getting closer to an Early Access release and they have a sweet new trailer.
Mainframe Defenders from Old Byte Apps is an in-development retro take on a squad-based strategy roguelike. They just announced today that they've now added a Linux demo.
Decemberborn Interactive recently released Cathedral, a homage to classic 8-bit and 16-bit classics with a large hand-crafted connected world to explore.
Rats, Bats, and Bones from Mark Begenisich looks like a great retro-styled strategy game, one that takes the gameplay idea of Tower Defense and replaces it with Traps.