Just writing to share that this was solved!

Looking at the "technical issues" thread by Larian QA, I saw the below:

Problem 4:
Strange graphical artifacts in game and very low fps

Solution
Go to your driver settings (nvidia or AMD) and reset 3d application settings to default. Forcing Anti-aliasing via drivers causes several graphics issues.

This did the trick. smile Main menu is fine, and wowza--the End of Time location is beautiful!! Thanks!