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

fcore/enemy/falling-enemies.sml

@@ -49,7 +49,7 @@ struct
       acc
     else
       let
-        val {x, y, jumped, variant} = Vector.sub (vec, pos)
+        val {x, y, variant} = Vector.sub (vec, pos)
 
         val size = Constants.enemySize
         val ww = Constants.worldWidth
@@ -59,21 +59,10 @@ struct
           (* filter out if player is attacking falling enemy *)
           updateList (pos - 1, vec, player, acc)
         else if Collision.isCollidingPlus (x, y, size, size, 0, 0, ww, wh) then
-          (* move falling enemy up or down depending on jumped *)
+          (* move falling enemy upwards *)
           let
             val updated =
-              if jumped < Constants.jumpLimit then
+              {x = x, y = y - Constants.moveEnemyBy, variant = variant}
-                { x = x
-                , y = y - Constants.moveEnemyBy
-                , jumped = jumped + Constants.moveEnemyBy
-                , variant = variant
-                }
-              else
-                { x = x
-                , y = y + Constants.moveEnemyBy
-                , jumped = jumped
-                , variant = variant
-                }
           in
             updateList (pos - 1, vec, player, updated :: acc)
           end
@@ -89,7 +78,7 @@ struct
       Vector.concat acc
     else
       let
-        val {x, y, variant = _, jumped = _} = Vector.sub (fallingVec, pos)
+        val {x, y, variant = _} = Vector.sub (fallingVec, pos)
 
         val x = Real32.fromInt x * ratio + xOffset
         val y = Real32.fromInt y * ratio + yOffset

fcore/game-type.sml

@@ -58,7 +58,7 @@ sig
     , nextPlatID: int
     }
 
-  type falling_enemy = {x: int, y: int, variant: EnemyVariants.t, jumped: int}
+  type falling_enemy = {x: int, y: int, variant: EnemyVariants.t}
 
   type game_type =
     { player: player
@@ -135,7 +135,7 @@ struct
     , nextPlatID: int
     }
 
-  type falling_enemy = {x: int, y: int, variant: EnemyVariants.t, jumped: int}
+  type falling_enemy = {x: int, y: int, variant: EnemyVariants.t}
 
   type game_type =
     { player: player