Aha; I’d forgotten about that.
From what I can see (based only on a few BGG images identified as for the new edition), the differences to the visuals are very slight indeed. (This one shows the previous version.) The actual artwork throughout looks essentially the same as before, with just a few new adornments.
- The box art is identical save for the lettering of the title.
- The plastic insert is transparent with a variant of the box art included behind it as well, so that looks nice (and has a practical benefit of indicating with colour which set of miniatures goes in which half).
- The miniature sculpts look identical to me.
- The board looks almost identical aside from emphasising the colour/position of the totem squares, and the score tracks are different.
- The megalith tile art looks identical to me, but it seems that the icons have been re-oriented wrt the central picture (previously each icon was at 90 degrees to the picture). I’d say this is the most noteworthy visual change.
- The transformation and action tiles are better differentiated with a more obvious border.
- The circular score tokens also have similar borders added.