diff --git a/objects/player/player.gd b/objects/player/player.gd
index ee3b6fe..286f2e1 100644
--- a/objects/player/player.gd
+++ b/objects/player/player.gd
@@ -80,6 +80,12 @@ func _ready() -> void:
 	state_chart.set_guard_property("red_feather", false)
 	# state chart debug
 	$StateDebugLayer/StateChartDebug.target = state_chart
+	# set lung size
+	if Game.difficulty == Game.Difficulty.SWEET:
+		oxygen_timer.set_wait_time(25)
+	if Game.difficulty == Game.Difficulty.PUNGENT:
+		oxygen_timer.set_wait_time(15)
+	oxygen_timer.start()
 
 func _physics_process(delta: float) -> void:
 	# snap sprite
diff --git a/objects/player/player.tscn b/objects/player/player.tscn
index d4675fa..ac130fb 100644
--- a/objects/player/player.tscn
+++ b/objects/player/player.tscn
@@ -1519,8 +1519,7 @@ custom_styles/bg = SubResource( 4 )
 script = ExtResource( 8 )
 
 [node name="OxygenTimer" type="Timer" parent="."]
-wait_time = 15.0
-autostart = true
+wait_time = 20.0
 
 [node name="JumpPeakTimer" type="Timer" parent="."]
 wait_time = 0.2
@@ -1543,8 +1542,8 @@ align = 1
 [connection signal="state_physics_processing" from="StateChart/Root/Movement" to="." method="_process_movement"]
 [connection signal="state_entered" from="StateChart/Root/Movement/Grounded" to="." method="_on_Grounded_state_entered"]
 [connection signal="state_physics_processing" from="StateChart/Root/Movement/Grounded" to="." method="_process_grounded"]
-[connection signal="state_physics_processing" from="StateChart/Root/Movement/Grounded/CanWalk" to="." method="_process_horizontal_movement_grounded"]
 [connection signal="state_physics_processing" from="StateChart/Root/Movement/Grounded/CanWalk" to="." method="_process_can_walk"]
+[connection signal="state_physics_processing" from="StateChart/Root/Movement/Grounded/CanWalk" to="." method="_process_horizontal_movement_grounded"]
 [connection signal="state_entered" from="StateChart/Root/Movement/Grounded/CanWalk/Still" to="." method="_on_Still_state_entered"]
 [connection signal="state_entered" from="StateChart/Root/Movement/Grounded/CanWalk/Walking" to="." method="_on_Walking_state_entered"]
 [connection signal="state_entered" from="StateChart/Root/Movement/Grounded/CanWalk/Blinking" to="." method="_on_Blinking_state_entered"]