One way to get a similar behavior is to use an instance variable and call it something like VectorX. Then, have two conditions:
So what this does is store your platformer VectorX in the instance variable, and use it when you're jumping/falling as a constant left/right speed until you land. You'll have to manually make the animation face the right way though since you'll still be able to "turn around" but not change your horizontal speed mid-air.
The thing with simulating left/right is that you will accelerate in the air which seems weird if you let go of everything, and the thing with this method is your jump distance will depend on your speed when you jump. With Ghouls and Ghosts it doesn't really matter because your speed is more or less constant, they have instantaneous acceleration and the jumps are always the same.