Mavericks seems to be a rather interesting shooter, one that will have both an open world mode and a Battle Royale mode and it turns out it plans Linux support too.
Klei have announced that the Don't Starve: Hamlet expansion that was announced in September last year, has moved to a December release. They've got a fancy new trailer though.
For those who love your Visual Novels and want something a little extra, Planet Stronghold 2 with RPG elements along with map exploration might be a good fit.
In Master Pyrox Wizard Smackdown, you face off against up to eight other wizards in small arenas. It has support for single-player against the AI, local co-op and online play too.
Pack your bags as you're going to Mexico in the first DLC for Railway Empire, which is out now with Linux support. A big free patch was also released, which sounds fantastic.