anchor.diff:     (hit-points :accessor hp    :initform nil        :initarg :hp    :type fixnum)
      (color      :accessor color :initform sdl:*cyan* :initarg :color :type sdl:color)))
   
  -(defclass item (unit) ())
  +(defclass item (unit)
  +  ((owner :initform nil)))
   
   (defclass tool (item) ())
   
  
positive.code: ;; This should either be turned into a macro or another lookup table
  
  ;; Macro could look like:
  (defmacro make-sprite (name filename)
    `(defparameter ,(concatenate 'string "*" `,name "-sprite-path*")
       (concatenate "#p" ,filename))
    `(defvar (concatenate 'string "*" ,name "-sprite*")))
  
  (defparameter *grass-sprite-path* #p"grass.png")
  (defvar *grass-sprite*)
  
negative.code: (defparameter *player-sprite-path* #p"player.png")
  (defvar *grass-sprite*)
  
  ;; TILES
  (defclass tile ()
    ((blocks-light :accessor blocks-light :initform nil)
     (blocks-move :accessor blocks-move :initform nil)
  