Here's a curious one. Evolvation, a space combat sim from HyperReuts originally supported Linux last year and after going through a revamp Linux support was removed. It's coming back though, as the developer has confirmed.
Feudal Alloy is certainly a unique theme, with you controlling medieval robots as a fish. The developer has now confirmed it's releasing with Linux support this month.
Valve may be gearing up for an interesting few years, as it seems Erik Wolpaw who helped write Portal, Half-Life: 2 episodes and more is now back at Valve.
TerraTech is one of the more interesting sandbox games I played last year, an open-world giving you a lot of freedom to explore and destroy while you create your own vehicles.
Despite releasing to negative reviews from users and critics, OtherSide Entertainment and 505 Games seem committed to fixing it up and gave an update about the upcoming Linux support.
Volcanoids, the game where you build a base onboard a massive steampunk-like moving drill is coming to Linux and the latest update sounds very positive.
Coming to Linux sometime this year, The End of the Sun is a first-person exploration and adventure game set in the world of Slavic rites, beliefs, legends and their everyday life. The developers recently showed some behind the scenes development information.
Linux Steam Integration, the project originally made while developer Ikey Doherty was working on the Solus Linux distribution now seems to be continuing on under Intel with their Clear Linux distribution.