I finished the game, but i didnt get any achivement.... Someone know what i can do?

just started level 66, didn't even move anything until then. Canceled fullscreen and went back into it and suddenly got the achievement for beating level 66. So i guess this wasn't meant to happen? PS: also nothing happens when beating level 66 for real, wondering if this is supposed to be like this?...

The title says it all. I want to play through again, but scrolling back from puzzle 66 each time (and having to remember where I stopped) is tiresome. Love the game!

So what do you think about "black + black = white" statement? Problematic.