diff --git a/test.py b/test.py
index 023ba19..2157e25 100644
--- a/test.py
+++ b/test.py
@@ -153,6 +153,7 @@ class Game:
 
     bgm:                Sound
     clock:              Clock
+    fps:                float
     frame:              int
     last_answered_at:   datetime
     now:                datetime
@@ -166,6 +167,7 @@ class Game:
         self.now = datetime.now ()
         self.screen = pygame.display.set_mode ((CWindow.WIDTH, CWindow.HEIGHT))
         self.clock = Clock ()
+        self.fps = FPS
         self.frame = 0
         self.objects = []
         self.bgm = Sound ('assets/bgm.mp3')
@@ -182,7 +184,13 @@ class Game:
             if obj.enabled:
                 obj.redraw ()
         pygame.display.update ()
-        self.clock.tick (FPS)
+        delta_time = self.clock.tick (FPS) / 1000
+        self.fps = 1 / delta_time
+        if delta_time > 1 / FPS:
+            for _ in range (int (FPS * delta_time) - 1):
+                for obj in self.objects:
+                    if obj.enabled:
+                        obj.update ()
 
     def _create_sky (
             self,
@@ -249,6 +257,11 @@ class GameObject:
 
     def redraw (
             self,
+    ) -> None:
+        self.update ()
+
+    def update (
+            self,
     ) -> None:
         self.x += self.vx
         self.y += self.vy
@@ -335,6 +348,8 @@ class Deerjika (Creature):
         width (int):                幅 (px)
     """
 
+    FPS = 30
+
     height:     int
     scale:      float               = .8
     surfaces:   list[Surface]
@@ -379,15 +394,21 @@ class Deerjika (Creature):
     def redraw (
             self,
     ) -> None:
-        surface = pygame.transform.scale (self.surfaces[self.frame % len (self.surfaces)],
+        surface = pygame.transform.scale (self.surfaces[self.frame * self.FPS // FPS
+                                                        % len (self.surfaces)],
                                           (self.width * self.scale, self.height * self.scale))
         self.game.screen.blit (surface, surface.get_rect (center = (self.x, self.y)))
         super ().redraw ()
+
+    def update (
+            self,
+    ) -> None:
         if (not self.balloon.enabled) and self.talking:
             self.talking = False
         if (self.balloon.enabled and self.balloon.frame >= FPS * 1.5
                 and not self.talking):
             self.read_out ()
+        super ().update ()
 
     def talk (
             self,
@@ -445,7 +466,7 @@ class CurrentTime (GameObject):
     ) -> None:
         for i in range (4):
             self.game.screen.blit (
-                    self.font.render (str (self.game.now), True, (0, 0, 0)),
+                    self.font.render (f"{ self.game.now }  { self.game.fps } fps", True, (0, 0, 0)),
                     (i % 2, i // 2 * 2))
         super ().redraw ()
 
@@ -557,6 +578,10 @@ class KitaSun (GameObject):
         surface = pygame.transform.rotate (self.surface, -(90 + math.degrees (self.arg)))
         self.game.screen.blit (surface, surface.get_rect (center = (self.x, self.y)))
         super ().redraw ()
+
+    def update (
+            self,
+    ) -> None:
         self.sun.compute (self.game.sky.observer)
         self.alt = self.sun.alt
         self.az = self.sun.az
@@ -564,6 +589,7 @@ class KitaSun (GameObject):
             self.arg = self.new_arg
         self.x = self.new_x
         self.y = self.new_y
+        super ().update ()
 
     @property
     def new_x (
@@ -620,6 +646,10 @@ class Jojoko (GameObject):
         surface.set_colorkey ((0, 255, 0))
         self.game.screen.blit (surface, surface.get_rect (center = (self.x, self.y)))
         super ().redraw ()
+
+    def update (
+            self,
+    ) -> None:
         self.moon.compute (self.game.sky.observer)
         self.alt = self.moon.alt
         self.az = self.moon.az
@@ -627,6 +657,7 @@ class Jojoko (GameObject):
             self.arg = self.new_arg
         self.x = self.new_x
         self.y = self.new_y
+        super ().update ()
 
     @property
     def phase (