diff --git a/Scripts/traps/trap3-tracing_bullet.gd b/Scripts/traps/trap3-tracing_bullet.gd
index 5efc7425..76360a75 100644
--- a/Scripts/traps/trap3-tracing_bullet.gd
+++ b/Scripts/traps/trap3-tracing_bullet.gd
@@ -15,10 +15,13 @@ var speed := 0.0
 var tracing := true
 var flying := false
 var wall_counter := 0
+var is_demo := false
+var effect_reparented := false
 @onready var feather_effect = $FeatherEffect
 @onready var leave_wall_detector = $Area2D
 @onready var wait_timer = $WaitTimer
 @onready var animation = $AnimationPlayer
+@onready var sprite = $AnimatedSprite2D
 
 
 static func initialize(pos: Vector2, dir: Vector2, speed: float) -> Trap3TracingBullet:
@@ -32,6 +35,8 @@ static func initialize(pos: Vector2, dir: Vector2, speed: float) -> Trap3Tracing
 
 
 func _ready() -> void:
+	if is_demo:
+		return
 	collision_layer = TRAP_COLLISION_LAYER
 	collision_mask = 0
 	leave_wall_detector.collision_mask = WALL_COLLISION_LAYER
@@ -45,6 +50,8 @@ func _ready() -> void:
 
 
 func _destroy() -> void:
+	$CollisionShape2D.set_deferred("disabled", true)
+	await get_tree().create_timer(0.1).timeout
 	queue_free()
 
 
@@ -104,3 +111,27 @@ func _on_wall_exited(_body: Node2D) -> void:
 	wall_counter -= 1
 	if wall_counter <= 0:
 		collision_mask = PLAYER_COLLISION_LAYER | WALL_COLLISION_LAYER
+
+
+#-------------------------
+
+
+func serialize_state() -> Dictionary:
+	return {
+		"type": "trap3-tracing_bullet",
+		"position": global_position,
+		"rotation": rotation,
+		"scale": sprite.scale,
+		"feather_effect": feather_effect.emitting
+	}
+
+
+func apply_demo_state(data: Dictionary) -> void:
+	global_position = data.get("position", Vector2.ZERO)
+	rotation = data.get("rotation", 0.0)
+	sprite.scale = data.get("scale", Vector2.ZERO)
+	feather_effect.emitting = data.get("feather_effect", false)
+	feather_effect.global_position = global_position
+	if !effect_reparented:
+		effect_reparented = true
+		feather_effect.reparent($"..")
diff --git a/Scripts/traps/trap4-conveyor.gd b/Scripts/traps/trap4-conveyor.gd
index 01716a6d..cf433143 100644
--- a/Scripts/traps/trap4-conveyor.gd
+++ b/Scripts/traps/trap4-conveyor.gd
@@ -11,6 +11,7 @@ var speed = trap_data["trap4-conveyor"]["speed"]
 var lifetime = trap_data["trap4-conveyor"]["lifetime"]
 var area_scale = trap_data["trap4-conveyor"]["scale"]
 var direction: Vector2
+var is_demo: bool = false
 var _is_disappearing: bool = false
 
 @onready var wave_animation: AnimatedSprite2D = $AnimatedSprite2D
@@ -34,6 +35,8 @@ static func initialize(pos: Vector2, dir: Vector2) -> Trap4Conveyor:
 
 func _ready() -> void:
 	# Trap should expire after the configured lifetime.
+	if is_demo:
+		return
 	scale = Vector2(area_scale, area_scale)
 	await get_tree().create_timer(lifetime).timeout
 	_destroy_trap()
@@ -64,3 +67,21 @@ func _on_body_entered(body: Node2D) -> void:
 func _on_body_exited(body: Node2D) -> void:
 	if body == Global.game_manager.player and body is CharacterBody2D:
 		body.external_velocity -= speed * direction
+
+
+#-----------------------------------------
+func serialize_state() -> Dictionary:
+	return {
+		"type": "trap4-conveyor",
+		"position": global_position,
+		"rotation": rotation,
+		"scale": scale,
+		"shader_reveal": wave_animation.material.get_shader_parameter("reveal")
+	}
+
+
+func apply_demo_state(data: Dictionary) -> void:
+	global_position = data.get("position", Vector2.ZERO)
+	rotation = data.get("rotation", 0.0)
+	wave_animation.material.set_shader_parameter("reveal", data.get("shader_reveal", 1.0))
+	scale = data.get("scale", Vector2.ZERO)
diff --git a/Scripts/traps/trap6-scanline.gd b/Scripts/traps/trap6-scanline.gd
index 5d762225..b6850a6f 100644
--- a/Scripts/traps/trap6-scanline.gd
+++ b/Scripts/traps/trap6-scanline.gd
@@ -17,6 +17,8 @@ var velocity := Vector2(0, 0)
 var speed := 5.0
 var line_pos := Vector2(0, 0)
 var time := 0.0
+var is_demo := false
+var hula_rotate := false
 
 @onready var visual_line = $Hulas
 
@@ -44,6 +46,8 @@ func _clamp_to_four_directions(dir: Vector2) -> Vector2:
 
 # Called when the node enters the scene tree for the first time.
 func _ready() -> void:
+	if is_demo:
+		return
 	visible = true
 	visual_line.visible = true
 	body_entered.connect(_on_body_entered)
@@ -52,6 +56,7 @@ func _ready() -> void:
 	if abs(line_dir.x) > 0.1:
 		rotation = PI / 2
 		var hulas = visual_line.get_children()
+		hula_rotate = true
 		for hula in hulas:
 			hula.rotation = -PI / 2
 
@@ -70,3 +75,31 @@ func _physics_process(delta: float) -> void:
 
 func _on_body_entered(_body: Node2D) -> void:
 	Global.player_hit.emit(damage)
+
+
+#-----------------------------------------
+func serialize_state() -> Dictionary:
+	return {
+		"type": "trap6-scanline",
+		"position": global_position,
+		"rotation": rotation,
+		"visual_line_modulate": visual_line.modulate,
+		"visual_line_position": visual_line.position,
+		"visual_line_scale": visual_line.scale,
+		"visual_line_rotation": visual_line.rotation,
+		"hula_rotate": hula_rotate
+	}
+
+
+func apply_demo_state(data: Dictionary) -> void:
+	global_position = data.get("position", Vector2.ZERO)
+	rotation = data.get("rotation", 0.0)
+	visual_line.modulate = data.get("visual_line_modulate", Color.WHITE)
+	visual_line.position = data.get("visual_line_position", Vector2.ZERO)
+	visual_line.scale = data.get("visual_line_scale", Vector2.ONE)
+	visual_line.rotation = data.get("visual_line_rotation", 0.0)
+	if !hula_rotate and data.get("hula_rotate", false):
+		hula_rotate = true
+		var hulas = visual_line.get_children()
+		for hula in hulas:
+			hula.rotation = -PI / 2