Solace Crafting from Big Kitty Games is an open world fantasy survival RPG, with an aim to be as open as possible and let you basically do whatever you please.
Huge Enemy - Worldbreakers is a rather impressive side-scrolling shoot 'em up that's officially released with Linux support, it also has a demo to try out.
Kingdoms and Castles is a game about building a city and defending it from invaders and dragons, the latest "Beautification Update" update expands your building options even more.
Pillars of Eternity II: Deadfire Seeker, Slayer, Survivor is the second major DLC pack coming for this ambitious RPG from Obsidian Entertainment. A combat-focused expansion, so prepare yourself.
From Orbit is an interesting sounding strategy game that will be coming to Linux next year. Set in deep space, you will be hopping from planet to planet as you try to find your way home.
The day is almost here, Blade Symphony the sword-fighting slash 'em up is getting a big update named Harmonious Prelude and it will release with Linux support on September 27th.
Stellaris is set to have some big changes with the next major update, along with some minor free content added to the Humanoids Species Pack and the Distant Stars Story Pack.
Dicey Dungeons from Terry Cavanagh, Marlowe Dobbe, and Chipzel is a great roguelike that quickly becoming a favourite of mine and this latest release is excellent.