Very good game! One of the best TD I have ever played.
"Dust to Dust" achievement should say 'disintegrate' and not 'desintegrate'. Unless its intentional. :)
So I tried to refresh and see if the bug will be gone... MY ENTIRE SAVE IS LOST. The stats are still showing correctly, but all the levels and upgrades are gone.
Let me be more specific:
One mage upgraded to maximum except movement, on the platform.
One healer upgraded like this: 9 on healing, 3 on range, 8 on health, 2 on movement.
Put the healer in a corner. She will get attacked sometimes, so you need to protect her without jumping off the platform, it's possible. sometimes you may need to move her just closer to you if you cant protect her from far.