anchor.diff:                         :offset (complex (/ (x size) 2) (* (y size) 3/4))
                          :image (make-instance 'anim :name :thopter)
                          :health 4 :firepower 3 :missiles 2)))
  +		       ;:health 200 :firepower 10 :missiles 5)))
            (subscribe (game-keys game) thopter)))
         ((:server :client)
           (let ((thopter1 (make-instance
  
positive.code:   (with-slots (parent offset size veloc timer missiles fire-rate) enemy
      (setf timer
            (ceiling (+ 5 (mt19937:random 30) (mt19937:random 30)) fire-rate))
      (if (> missiles 0) 
  	(progn (decf missiles) 
  	       (make-instance
  		'enemy-missile
  		:parent parent 
  		:offset (+ offset (/ size 2) )
  		:depth -1
  		:veloc veloc
  		:image (make-instance 'image :name :enemy-missile-s)))
  	(shoot enemy event))))
  
  (defmethod collide ((enemy enemy) event)
    (with-slots (parent offset size depth veloc health firepower missiles) enemy
  
negative.code:   (with-slots (parent offset size depth veloc) missile
      (when (and parent (or (and (typep missile 'missile)
  			       (typep (event-hit event) 'enemy))
                            (typep (event-hit event) 'explosion)))
        (let ((explosion (make-instance 'anim :name :explosion)))
          (make-instance 'explosion :parent parent
                         :offset (+ offset (/ size 2) (/ (size explosion) -2))
                         :depth depth :veloc (/ veloc 2)
                         :image explosion
                         :timer 10))
        (detach parent missile))))
  
  (defmethod collide ((missile enemy-missile) event)
    (with-slots (parent offset size depth veloc) missile
      (when (and parent 	  (and (typep missile 'enemy-missile)
  			       (typep (event-hit event) 'thopter)))
        (let ((explosion (make-instance 'anim :name :explosion)))
          (make-instance 'explosion :parent parent
                         :offset (+ offset (/ size 2) (/ (size explosion) -2))
  