Hi I have just completed this level it took me absolutely ages. First the Yin tile is situated second row down from the top and 8 tiles in from either end (including bricks) at the bottom of the stack. And the Yang tile the same position but on the bottom row. If you keep letting the timer run out you will eventually be offered the option to advance but you would lose half your score. I kept at it and completed the level without doing this. If you dont have any luck take the option of a restart with a shuffle and try a new layout. The magnifying glasses enable you to see what tiles are in the stacks, click on each magnifier and slowly run the pointed end of the beam down the stack and you will see each tile in the stack, remember what tiles are in each stack ,use the butterflies the lift the top tile to access the lower tiles. I managed to complete the level and have a spare butterfly left. Let me know if you need any more info. Regards. Ken