I honestly can't get enough of good top-down shooters that have a dark atmosphere and Xenosis: Alien Infection [Official Site, Fig Campaign] looks rather good. There's a few easy ways to gain my attention: mention an awesome Amiga game like Alien Breed as inspiration, include Aliens and let me squash them—check all points!
It's being developed by Nerd Rage Studios, the same developer who made Jump Gunners, a game that works really nicely on Linux (pretty fun too) so they've already proven they can do a good Linux build. Check out the trailer:
As shown at the end, it's currently crowdfunding on Fig. The campaign has only just launched, so it might ask you to keep it a secret, although the developer did mention to share it around anywhere. The developer is seeking $25K, which isn't a huge amount to make a game. They've actually been developing it for 18 months already, with the previous game helping to partially fund this.
It's a story-driven single-player experience, featuring hand-crafted levels that blends retro 2D pixel art, with 3D modern lighting, dynamic shadows and 3D positional audio and it certainly seems like it has a great atmosphere from the trailer. It's not a straight run and gun shooter either, with stealth elements enabling you to use the shadows, turn off and disable lighting and find other ways to survive.
Even better, is that I've been speaking to the developer and I will likely be able to livestream an early Linux build on our Twitch channel.