diff --git a/scripts/player.gd b/scripts/player.gd
index 06a2f78..682e204 100644
--- a/scripts/player.gd
+++ b/scripts/player.gd
@@ -34,11 +34,19 @@ func _ready() -> void:
 	# scene root.  The lookup walks the full subtree (recursive=true) so
 	# it finds the marker whether it is a direct child of the level or
 	# nested deeper.
-	var spawn := get_tree().current_scene.find_child("PlayerSpawn", true, false)
+	#
+	# current_scene is null in headless --script mode and in any scene
+	# before the main scene is fully swapped in, so guard it rather than
+	# blindly dereferencing.
+	var current_scene: Node = get_tree().current_scene
+	var spawn: Node = null
+	if current_scene != null:
+		spawn = current_scene.find_child("PlayerSpawn", true, false)
+
 	if spawn is Node3D:
-		global_position = spawn.global_position
+		global_position = (spawn as Node3D).global_position
 		# Align player forward with spawn yaw (optional polish).
-		var spawn_yaw := spawn.rotation.y
+		var spawn_yaw := (spawn as Node3D).rotation.y
 		rotation.y = spawn_yaw
 	else:
 		push_warning("player.gd: no PlayerSpawn marker found; spawning at origin")
diff --git a/scripts/smoke_test_player.gd b/scripts/smoke_test_player.gd
index 20826d0..02e4c0a 100644
--- a/scripts/smoke_test_player.gd
+++ b/scripts/smoke_test_player.gd
@@ -7,8 +7,8 @@ extends SceneTree
 ## Loads the test level, verifies the player is present, spawned at the
 ## PlayerSpawn marker, and has the expected CharacterBody3D structure.
 
-var passed := 0
-var failed := 0
+var _passed := 0
+var _failed := 0
 
 
 func _initialize() -> void:
@@ -20,60 +20,65 @@ func _run() -> void:
 	await process_frame
 	print("SMOKE: loading test level scene")
 
-	# Load the test level scene (which now includes the player).
+	# Load the test level scene (which includes the player).
 	var packed: PackedScene = load("res://scenes/worlds/test_level.tscn")
 	var level: Node3D = packed.instantiate()
+
+	# Order matters: set_current_scene() requires the node's parent to already
+	# be root, so add_child() must come first. This mirrors what a real
+	# change_scene_to_packed() does at runtime.
 	root.add_child(level)
+	current_scene = level
+
 	print("SMOKE: level instantiated, waiting for ready")
 	await level.ready
 	print("SMOKE: level ready")
 
 	# 1. Verify the player node exists in the scene tree.
-	var player := level.get_node("Player")
+	var player: Node = level.get_node("Player")
 	_check("Player node exists in test level", player != null)
 	_check("Player is a CharacterBody3D", player is CharacterBody3D)
 
 	# 2. Verify the player has the expected child structure.
-	var collision := player.get_node("CollisionShape3D")
+	var collision: Node = player.get_node("CollisionShape3D")
 	_check("Player has CollisionShape3D", collision != null)
-	_check("CollisionShape3D has a shape", collision.shape != null)
+	_check("CollisionShape3D has a shape",
+		   collision is CollisionShape3D and (collision as CollisionShape3D).shape != null)
 
-	var mesh := player.get_node("CapsuleMesh")
+	var mesh: Node = player.get_node("CapsuleMesh")
 	_check("Player has CapsuleMesh", mesh != null)
-	_check("CapsuleMesh has a mesh", mesh.mesh != null)
+	_check("CapsuleMesh has a mesh",
+		   mesh is MeshInstance3D and (mesh as MeshInstance3D).mesh != null)
 
 	# 3. Verify the player spawned at the PlayerSpawn marker position.
 	var spawn_marker: Marker3D = level.get_node("PlayerSpawn")
 	_check("PlayerSpawn marker exists", spawn_marker != null)
 
 	# The player's _ready() should have moved it to the spawn marker's
-	# global position.  Since both are direct children of the root, their
-	# global positions equal their local positions.
+	# global position. Since both are direct children of the level root
+	# (and the level root is at the origin), their global positions equal
+	# their local positions.
 	var expected_pos: Vector3 = spawn_marker.global_position
 	_check("Player spawned at PlayerSpawn position",
 		   player.global_position == expected_pos)
 
-	# 4. Verify the player script class_name is correct.
-	var script := player.get_script()
+	# 4. Verify the player script class_name is correct and has the
+	# movement constants defined.
+	var script: GDScript = player.get_script() as GDScript
 	_check("Player has a script attached", script != null)
-	_check("Player script is Player class", script is GDScript)
+	var constants: Dictionary = script.get_script_constant_map()
+	_check("Player has WALK_SPEED constant", constants.has("WALK_SPEED"))
+	_check("Player has GRAVITY constant", constants.has("GRAVITY"))
+	_check("Player has JUMP_VELOCITY constant", constants.has("JUMP_VELOCITY"))
 
-	# 5. Verify the player has movement constants defined.
-	_check("Player has WALK_SPEED constant",
-		   script.get_constant("WALK_SPEED") != null)
-	_check("Player has GRAVITY constant",
-		   script.get_constant("GRAVITY") != null)
-	_check("Player has JUMP_VELOCITY constant",
-		   script.get_constant("JUMP_VELOCITY") != null)
-
-	print("\n=== SMOKE RESULT: %d/%d passed ===" % [passed, passed + failed])
-	quit(0 if failed == 0 else 1)
+	print("\n=== SMOKE RESULT: %d/%d passed ===" % [_passed, _passed + _failed])
+	quit(0 if _failed == 0 else 1)
 
 
 func _check(description: String, condition: bool) -> void:
 	if condition:
 		print("  PASS: ", description)
-		passed += 1
+		_passed += 1
 	else:
 		printerr("  FAIL: ", description)
-		failed += 1
+		_failed += 1