don't make 'falling' enemies come back down (fall), but lift them up instead, filtered when reaching beyond the top of the world. It's a little more fluid with current physics for enemies to be 'spirited away' rather than fall.

fcore/enemy/enemy-behaviour.sml

@@ -425,7 +425,7 @@ struct
          * fallingEnemies *)
         let
           val fallingList =
-            {x = x, y = y, variant = #variant enemy, jumped = 0} :: fallingList
+            {x = x, y = y, variant = #variant enemy} :: fallingList
         in
           (enemyList, fallingList)
         end
@@ -472,7 +472,7 @@ struct
          * fallingEnemies *)
         let
           val fallingList =
-            {x = x, y = y, variant = #variant enemy, jumped = 0} :: fallingList
+            {x = x, y = y, variant = #variant enemy} :: fallingList
         in
           (enemyList, fallingList)
         end