Very hard game, but doable. I agree with previous comments.
Here are a few other tips and feedbacks:
- A game speed slider would be beneficial. It’s easily doable through Engine.time_scale if you used delta in your 
_physics_process. - When catching you, the ghost taking you back to the start seems to be animated through a tween with a fixed duration, making it very punishing near the end. You could set duration based on distance with 
duration = distance/speed. - I don’t think anyone likes bonking on the ceiling, especially when followed by a bunch of precise jumps, with a high-speed character and no coyote time.
 - When the ghost drops you while you are inside terrain, you are stuck and need to restart the game.
 - Adding a full-screen button to the web export (it’s an option in 
edit gameon itch.io) would make it easier to play (providing you handle window resizing), because I had to make the browser full-screen then carefully scroll to see the whole game screen. - You should make the end more rewarding. I know you probably didn’t have time, but at least queue_freeing the ghost when reaching the top would be great.