Push the up arrow on your keyboard: both Edna and her shadow go up.
Push the left arrow on your keyboard: Edna goes left, shadow goes right.
Push the right arrow on your keyboard: Edna goes right, shadow goes left.
Push the down arrow on your keyboard: both Edna and her shadow go down.
Bad guys:
A small critter that looks like a Baby Buzz.
An imp that looks like a mini brain tree.
A little black bat with sharp teeth.
A tiny gray ghost that looks freaky.
Watch them for a little while, and you should be able to tell where they will go next and avoid them. If Edna (or her shadow) touch one, Edna (or her shadow) is trapped.
Bonuses:
The golden pocket watch (adds a bit of time).
The red bottle (reverses Edna’s direction).
The green orb (stuns all the enemies).
To successfully complete a level you need to gather ALL the ingredients and direct Edna and her shadow both to the cauldron. – bl0kje