Beware a game breaking bug when playing.

Theres a part when you enter a new section of the map to explore. You can find 3 crystal towers defended by groups of cultists. Do not destroy the towers. They do not respawn when the main story quest comes and wants you to do it then.

The towers were one if the first things I found when entering the new area, and naturally I killed the enemies and destroyed the tower. I would have lost maybe 20 hours of gameplay if I reloaded from a point before the towers. Instead I uninstalled the game and never played again.