Puppygames, a developer who has supported Linux for many years are now making their games free for Linux gamers and they've already started with Basingstoke.
What is Basingstoke? It's a dark and tense roguelike that mixes in stealth and action elements, it's not really like anything else and I'm actually a pretty big fan of it. I livestreamed it on our Twitch Channel around the release and had a huge amount of fun. That said, I'm a fan of basically anything that comes from Puppygames, with Revenge of the Titans being another awesome game they made.
Take a peek:
They're doing it on itch.io since itch offer more flexible funding models, as well as itch being more generous overall with developers able to give back whatever they want from sales to itch. While free, you can decide to donate money when you first go to claim it if you like the idea.
When they have time, they will be putting their other games on itch and doing the same.
Find Basingstoke on itch now. They also have a Patreon, to help fund their next game, Battledroid, which is "a massively multiplayer asynchronous online strategy war game" and of course that will support Linux too.