I liked the idea of the ghosts providing different utilities in order to help the player escape. However, in the final level the ghosts became obstacles and felt like a hindrance, which goes against the small narrative you've set up. I think you were going for a Kaizo Mario-esque final level where formerly helpful utility is now an obstacle, which was a nice change of pace from a platforming perspective. However, it was disconcerting to think that the ghosts that were helping me were now hindering me for no given reason.
Loved the graphics, though the sections involving the different coloured fields made certain platforms and obstacles hard to see.
The controls felt responsive, but a number of platforming sections had a low margin of error.
The sections with the fields were novel though could have used an explanation. For example, the purple field was introduced early on and then reappeared again in a later level though without the same graphical effects. I knew it would affect my jump in some way, but I was uncertain if it would be affected in the same way as the first time I encountered it.
Some of these platforming sections would be more reasonable if the camera was zoomed out a little more in order to allow the player to plan ahead or give the player a chance to react sooner. For example, the aforementioned section with the purple field had spikes in the ceiling which were just outside of my camera view. As I was uncertain how the field would affect my jump, I ended up dying when I experimented and attempted to jump across because the field quickly accelerated the character into the ceiling spikes.
The puzzles were interesting, and the ghost that provides hints is a nice bonus. However, some checkpoints would be helpful, as the player would likely die due to a misjudged jump across the acid or accidentally push a crate too far when attempting to get them onto a switch causing a full level restart.
It is a fun puzzle platformer that can be refined further.