anchor.diff:      (mapc #'update messages)
       (resolve-collisions game)))
   
  -(defun resolve-collisions (game)
  +(defmethod draw ((game game))
  +  (draw (background game))
  +  (mapc #'draw (messages game))
  +  (sdl:draw-string-shaded-* (format nil "Player damage: ~a" (damage (player game)))
  +			    5 5 sdl:*red* (sdl:color :a 0))
  +  (sdl:draw-string-shaded-* (format nil "Enemies downed: ~a" (score (player game)))
  +			    5 15 sdl:*red* (sdl:color :a 0))
  +  (draw (player game))
  +  (mapc #'draw (enemies game))
  +  (mapc #'draw (projectiles game)))
  +
  +(defmethod take-a-step ((game game))
  +  (unless (paused-p game)
  +    (update game)
  +    (incf (current-frame game)))
  +  (draw game)
  +  (when (paused-p game)
  +    (draw-pause-screen)))
  +
  +(defmethod resolve-collisions ((game game))
     (loop for enemy in (enemies game)
          do (loop for projectile in (projectiles game)
   	     do (cond ((and (eql (player game)
  
positive.code: 			    sdl:*red*
  			    (sdl:color :a 0)))
  
  (defmethod draw ((game game))
    (draw (background game))
    (mapc #'draw (messages game))
    (sdl:draw-string-shaded-* (format nil "Player damage: ~a" (damage (player game)))
  			    5 5 sdl:*red* (sdl:color :a 0))
    (sdl:draw-string-shaded-* (format nil "Enemies downed: ~a" (score (player game)))
  			    5 15 sdl:*red* (sdl:color :a 0))
    (draw (player game))
    (mapc #'draw (enemies game))
    (mapc #'draw (projectiles game)))
  
  ;;;
  ;;; Key event handling
  ;;;
  (defun handle-key-event (key game &key (event-type :key-down))
    (cond ((eql event-type :key-down)
  	 (register-key-press key game))
  	((eql event-type :key-up)
  
negative.code:    (current-frame :initform 0 :accessor current-frame)
     (paused-p :initform nil :accessor paused-p)))
  
  ;;;
  ;;; Generic functions
  ;;;
  (defgeneric take-a-step (game))
  (defgeneric resolve-collisions (game))
  (defgeneric pause-screen (game))
  (defgeneric handle-key-event (key game &key))
  
  ;;; Game methods
  (defmethod update ((game game))
    (with-slots (running-p player background projectiles enemies messages enemy-counter) game
      (update background)
  