Glad you enjoyed it! The movement issue with the walls stems from a problem with the acceleration in the floaty/space levels. It would take forever to go back the other direction if you were up against a wall and the only solution we could think of in time was to check if there was collision and set the velocity to 0 and to use move_and_collide(). Afterwards, we found that you can do velocity.slide() to slide along the wall while also using move_and_collide():
var collision = move_and_collide(velocity * delta)
if collision:
velocity = velocity.slide(collision.get_normal())
Facepalm moment, next time I'll make sure to scroll alllll the way to the bottom of the docs!