Nathan, would you explain (or add a bonus tutorial video) showing how to orient/rotate the Player and Enemy to the slopes when they move along them (like in the image I linked below) and then straighten back up when moving along a flat surface or jumping? It's weird they go along the slopes with their corners.
KidsCanCode has a really nice article talking just about that. I recommend it: http://kidscancode.org/godot_recipes/2d/2d_align_surface/