Playing on windows version and I've noticed that jumping continuously onto a ceiling or the underside of a ramp (preferably one very close to a floor) sometimes lets you move around in the ceiling as if it was a wall and
sometimes even phase right trough the ceiling/ramp (I've only managed to phase trough
the wooden rail with the train)
(pictured here me walking on the ceiling above the ceiling fan, you can only move for a short while before falling just like on a wall)