War Brokers is an indie FPS that has many different game modes, including a Battle Royale mode. Their Linux support is in good shape and they've pushed out another good update.
The RPG title has finally gone forward with its promised Linux support and now has an opt-in beta on Steam. I've had the chance to play a little and have enjoyed what I have seen.
Mable & The Wood follows a shape-shifting girl whose power might actually be destroying the world she's trying to help save. It looks and sounds all rather interesting.
Slime-san is an excellent example of how to do a simple-looking platformer, filled full of awesome content and some quite difficult levels. After getting a few free expansions it's now getting a level editor.
You will be forgiven for not knowing about BlazeRush, since it's an oldie released back in 2014. Taking another look at it recently with the help of my trusty side-kick I've found it to be an exceptionally fun co-op experience on Linux.
Molecats is a little like Lemmings but instead of telling little creatures to do things, you flip environment tiles around to direct them where to go. It released in full today.
Ludic Studios are bringing some violent arcade slashing action to Linux with Akane. Set in 2121 in Mega-Tokyo, it will see you take on the Yakuza with a lot of bloodshed.