sample capx, here uses sine behavior to replace platform behavior for character moving.
Bullet has two states:
Go away : rejecting by obstacles
Go back: rejecting by obstacles and attracting by character
Try and error to get parameter A,B,m,n of this behavior.
I'm trying to mod this with the car engine to get that smooth, floaty look that works so well with the knife. Whereabouts should I place my accelerate and left/right simulations? The bullet in your example is a great proof-of-concept, but the "rotate 10 degrees" gives it a fluttery look, and the car behavior has a nice bounce when it hits the solids.