Some very interesting ideas and mechanics in this! I really liked the idea of controlling a ghost to help the player progress. It reminds me a lot of the gameplay in the Planet of Lana if you've played that game.
I also appreciated that there is a skill element (with timing the jump and how "hard" you jump) to the game too and not just purely puzzle solving.
I did come across a bit of jank when trying to mask out walls whilst the character was inside the same area. Sometimes the ghost would push the player out depending on which squares are selected.
Other than that, really good job on this one!