Q

You unlock SECRET 1 after completing a few levels in PRIMARY 2. You'll also need to complete some levels out of the first 10 in SECRET 15 before the full twenty levels are available to you.

For this achievement you'll need to complete Q.11 using just 1 drawing. Create a line at the top of the screen, and at the end of the line make a small piece pointing downwards. When this drops it should swing around, knocking the pink piece out. It may take a few attempts to get it just right, as the tower is quite easy to knock over.

A slightly different approach than the solution above. It simply wasn’t working for me. After just a few attempts I nailed it. Hope it helps!