On the Nancy level, after a decent bit of playing through the level usually when its near complete, it will consistently randomly end the level saying "You Win" but the next level would not unlock. If I attempted to go back into the Nancy level to try again, it would not allow me to move any columns and the top left square would have a red dotted highlight over it. I had to alt f4 to get out. I did this probably 5 times in a row
That.... is a fascinating bug, hadn't seen that one yet! I'll look into it (Are you on Windows 10?), but as a workaround, you can easily hack your savefile :D it's in %appdata%/Local/AIMatch3 , backup the enemies.ini and unlocks.ini and then add Nancy to enemies.ini and add Lilly to unlocks.ini. That should get you going again!