I got to the third checkpoint, then gave up after a couple dozen attempts at crossing the giant roller section. But that means the gameplay was fun enough for me to keep trying much longer than I would for many of the other entries in the jam.
The platforming is more difficult than it looks because the character has a lot of momentum, jumps off sloped surfaces give you horizontal momentum that's hard to correct without oversteering, and landing on the edge of a platform tends to lead to the capsule-shaped protagonist sliding off. These are legitimate design choices but they did ramp the difficulty up.
In the room with the red and cyan boxes, I could not get the red box to land on a button. It would always go flying off when I tried to push it onto a button. Eventually I realized I could skip past that room by standing on the red box and jumping over the wall.
The ghost system doesn't seem like it adds much to the core 3D platforming gameplay. All of the sections I saw involved you just waiting for the ghost to do its thing, or having it stand on a button. Maybe you did more with it in the parts of the game I didn't reach.
I like the design for the main character.