I literally just unlocked this achievement.
You have to finish the first five shows to do it, I initially tried completing the first show five times over and it didn't unlock but once I'd finished the fifth show it popped.
The hardest part to getting this is the final rounds.
The first show with the light out is tricky but doable
The second show with the boxes is a breeze and can easily help you net the Perfectionist achievement.
The third round however with the targets is a little more difficult, I found putting a blanket over my shoulders helped to make my shadow bigger to help you cover them.
I've put a video below of me finishing this stage using the blanket technique
The fourth round is a mirror image round, where you have to do the opposite of what is shown on the screen, I found going into the shape and edging left or right helps with this one.
The fifth round you have no shadow so have to guess the position, I found it was pretty generous with this. Also the outline of the hole lights up different colours depending on how close you are to the right shape.
Hope this helps :)