remove enemyTree (quad tree holding enemies) from game type as this is not static geometry and, since enemies are moving every frame, this should also be regenerated on every frame

fcore/player.sml

@@ -422,7 +422,7 @@ struct
   (* only checks for collisions with environment (walls and platforms) *)
   fun getEnvironmentPatches (player, game) =
     let
-      val {walls, wallTree, platformTree, platforms, enemyTree, enemies, ...} =
+      val {walls, wallTree, platformTree, platforms, enemies, ...} =
         game
 
       val {x, y, attacked, mainAttack, ...} = player