[zkarcher]

My attempt at Level 1:

  class Player
    def play_turn(warrior)
      warrior.walk!(:right)
    end
  end

The warrior keeps bumping in to a wall, and the code fails.

This is counter-intuitive, because the exit is to the right of the warrior. I can't endure another N levels of nonintuitive frustration, sorry.

[lloeki]

actually the warrior starts facing right (which is not specified but could be supposed). so :right is actually moving down, since all movements are relative, which is inferred by :forward and :backward being present and :up :down missing, which I suppose would rather be :north :south :east and :west. Once you also understand that tips really are not, but the necessary API doc, well, it's smooth sailing.