     body -1000 -10 cpv >>p drop
     body 400 0 cpv >>v drop
 
-    space cpCircleShapeAlloc body 8 0 0 cpv cpCircleShapeInit cpSpaceAddShape :> shape
-    shape
-    [ shape>> 0 >>e drop ]
-    [ shape>> 0 >>u drop ] bi ;
+    space cpCircleShapeAlloc [ body 8 0 0 cpv cpCircleShapeInit cpSpaceAddShape drop ] keep
+        :> shape
+    shape shape>>
+        0 >>e
+        0 >>u
+        drop ;
 
 M: chipmunk-world end-game-world
     space>>

        open-window
    ] with-ui ;


                x image-width 2 / - 0.05 0.0 1.0 uniform-random-float * + 2 *
                image-height 2 / y - 0.05 0.0 1.0 uniform-random-float * + 2 *
                make-ball :> shape
                space shape shape>> body>> cpSpaceAddBody drop
                space shape cpSpaceAddShape drop
            ] when
        ] each
