This was originally conceived as a BART project for completion during the lion kingdom's commute, but the commutes never returned so it has manely died.  There are much more practical things a lion can do when not stuck on a train.  

The last efforts were just on the physics system instead of any more art.  There was an attempt to use move_and_slide instead of the proper physics system.

It would pitch & roll to properly line up with the imaginary floor.  When it came time to yaw to line up with the walls FUGGEDABOUDIT.  Godot wasn't doing anything to the orientation.  It purely read the gravity vector to determine the pitch & roll.  Then it used the collision coordinates on the walls to determine which way to yaw.  Just doing this manually made it go crazy, so no amount of godot replacement would make any difference.

Reducing it beyond move_and_slide, to where it just slides on the imaginary floor instead of jumping, would make it quite boring.