anchor.diff:  
                   [// tile map
                    Content.tileMap Simulants.FieldTileMap.Name
  -                    [Entity.PublishChanges == true
  -                     Entity.Depth == Constants.Field.BackgroundDepth
  +                    [Entity.Depth == Constants.Field.BackgroundDepth
                        Entity.TileMapAsset <== model --> fun model ->
                           match Map.tryFind model.FieldType data.Value.Fields with
                           | Some fieldData -> fieldData.FieldTileMap
  
positive.code:                         let model = FieldModel.updateFieldTransitionOpt (constant None) model
                          let model =
                              FieldModel.updateAvatar (fun avatar ->
                                  let avatar = AvatarModel.updateDirection (constant fieldTransition.FieldDirection) avatar
                                  let avatar = AvatarModel.updateIntersectedBodyShapes (constant []) avatar
                                  avatar)
  
negative.code:                 just world
  
              | MoveAvatar position ->
                  let world = Simulants.FieldAvatar.SetCenter position world
                  let world = World.setBodyPosition position (Simulants.FieldAvatar.GetPhysicsId world) world
                  just world
  
              | PlaySound (delay, volume, sound) ->
  