Just like the title said.
Beat the Game Developer III Achievement Guide
Before First Enchanted Twig Doll
Before you follow this guide make sure you’ve memorized the majority of the locations for keys and the entire map.
When you spawn in head towards the Mansion.
Head inside and find the Gate Key, after you’ve located it head upstairs.
Find the House Key and take a Wtich Hair, after head towards the Puppy Gate through the kitchen door.
Unlock the Gate and head over to the nearby Garden Shears.
After you’ve acquired the Garden Shears head over back to the Gate and snip a Puppy Tail, now head to the Graveyard and take the farthest Twig Doll. (While doing this make sure to grab a Rose from a nearby tree)
Now head back into the Mansion and take a left into the Children’s room, take the path through the Basement into the Cauldron room.
Put the ingredients into the Cauldron but don’t pick up the enchanted doll yet, then head back to collect more ingredients.
Before Last 5 Enchanted Dolls
Continue collecting ingredients and head back into the Cauldron room, there should be the enchanted doll in the cauldron if you’ve listened to the instructions in “Before first enchanted doll”.
Stand far away enough from the Cauldron to make sure you don’t drop your twig doll into the cauldron and have to waste time. Take the Enchanted Doll and puncture it on the nearby spikes.
Quickly grab the Normal Twig Doll that you dropped and put the ingredients into the cauldron.
Continue using this strategy until you only have 5 dolls left (Not including the one that should be in the Cauldron already).
If you move fast enough the witch wont be a problem yet.
Last Steps of the Game
As soon as the number of Enchanted dolls hits 5 take the potion of speed nearby in the basement
Continue grabbing Witch Hair from the upstairs and taking the farthest Twig Dolls (Only take one potion per Enchanted Doll).
Once your all out of Speed potions begin taking Invisibility potions (They’re the ones right next to the speed ones).
Depending on your luck you will either be at 3 or 2 Enchanted Dolls left Once you only have two Enchanted Dolls left Head to the basement make sure your invisible and put one Enchanted Doll on the Spike, Then run over to the invisibility potions just in case, If the Witch is attacking you and you drink one she will still attack.
Once She is done yelling pick head back to the Cauldron and put the last Enchanted Doll on the spike, Stand behind the Cauldron and wait for her to be knocked unconscious, pick her up and head back to the van.
I’ve used this strategy Twice and besides a couple of failed attempts it seems to be the easiest way of getting this achievement.