Doing true enemies that move around the map is a little more complicated because they basically have to move like the player, but instead of waiting for input from the user to move via btnp() commands, they just have their own decisions to make on when and where they move. On top of that, if you only want them to move on specific tiles, you'd need a separate can_move() function for enemies that uses those specific tiles, instead of the generic "wall" tiles that the player uses to determined if they can't move somewhere. I hoe that makes sense.
It's definitely possible, but it does take quite a bit more code. If I have some time, I will try to make a video showing it.