Just a short update. Yesterday Unity team released Unity 5.3.2p4 and it fixes several Linux issues reported by our players (black/pink screen, visual artifacts, etc).
We decided to release v1.6.7 built with Unity 5.3.2p4. It also has a few non-Linux related improvements and fixes.
As always you can find the detailed list of change on AtomicTorch Forums.
Enjoy the game!