I got the idea for this from someone in the irc chatroom (I forget who) & it's a fun control system that I thought a C2 beginner might find useful to examine, or better yet an experienced user might expand upon & share their results.
It works by making the player a spinning disc, with left & right move keys setting the angular velocity. A ground detector sprite determines when you can jump, detecting overlaps with a family of 'solids' (ie. immovable physics sprites).
High linear damping & some additional downward force is the key to making the player physics settle down faster & feel more like the platformer behaviour.
There's a basic platformer sprite in the scene for comparison (arrow key control for that, & WASD for the physics one), & you'll see the weak point of the physics player is the air control which I could never get to feel right. Maybe someone could have a go at some better code for that.