Just a short update. Yesterday Unity team released Unity v5.3.2p4 and it fixes several Linux issues reported by our players (black/pink screen, visual artifacts, etc).
We decided to release v1.6.7 with a few non-Linux related improvements and fixes.
As always you can find the detailed list of change on our forums[http://forums.atomictorch.com/index.php?topic=851.msg5415#msg5415].
Enjoy the game!