プレイヤーを動かすと、スプライトであるプレイヤーと風船が吃音するのはなぜだろうか。

モーションコントロールであるWASDキーを使用すると、フレームがドロップし、基本的にゲームが停止します。水風船を動かすはずですが、動かなくなると水風船も動きます。どちらもスプライトです。スプライトファミリーが2つあるので、混乱させたかもしれません。

main.py：

import pygame
from player import Player
from projectile import WaterBaloon

# Start the game
pygame.init()
game_width = 1000
game_height = 650
screen = pygame.display.set_mode((game_width, game_height))
clock = pygame.time.Clock()
running = True

bg_image = pygame.image.load("../assets/BG_Sand.png")

#make all the sprite groups
playerGroup = pygame.sprite.Group()
projectilesGroup = pygame.sprite.Group()

#put every sprite class in a group
Player.containers = playerGroup
WaterBaloon.containers = projectilesGroup
#tell the sprites where they are gonna be drawn at
mr_player = Player(screen, game_width/2, game_height/2)

# ***************** Loop Land Below *****************
# Everything under 'while running' will be repeated over and over again
while running:
    # Makes the game stop if the player clicks the X or presses esc
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False
        if event.type == pygame.KEYDOWN and event.key == pygame.K_ESCAPE:
            running = False
            
        #player input that detects keys (to move)       
        keys = pygame.key.get_pressed()
        if keys[pygame.K_d]:
            mr_player.move(1, 0)
        if keys[pygame.K_a]:
            mr_player.move(-1, 0)
        if keys[pygame.K_w]:
            mr_player.move(0, -1)
        if keys[pygame.K_s]:
            mr_player.move(0, 1)
        if pygame.mouse.get_pressed()[0]:
            mr_player.shoot()
#blit the bg image
        screen.blit((bg_image),(0, 0))
#update the player
        mr_player.update()
#update all the projectiles
        for projectile in projectilesGroup:
            projectile.update()
            
        # Tell pygame to update the screen
        pygame.display.flip()
        clock.tick(60)
        pygame.display.set_caption("ATTACK OF THE ROBOTS fps: " + str(clock.get_fps()))

player.py：

import pygame
import toolbox
import projectile
#Players Brain
class Player(pygame.sprite.Sprite):
#player constructor function
    def __init__(self, screen, x, y):
        pygame.sprite.Sprite.__init__(self, self.containers)
        self.screen = screen
        self.x = x
        self.y = y
        self.image = pygame.image.load("../assets/player_03.png")
        #rectangle for player sprite
        self.rect = self.image.get_rect()
        self.rect.center = (self.x, self.y)
        #end of rectangle for player sprite
        self.speed = 8
        self.angle = 0
        
    #player update function
    def update(self):
        self.rect.center = (self.x, self.y)

        mouse_x, mouse_y = pygame.mouse.get_pos()
        self.angle = toolbox.angleBetweenPoints(self.x, self.y, mouse_x, mouse_y)
            
        #get the rotated version of player
        image_to_draw, image_rect = toolbox.getRotatedImage(self.image, self.rect, self.angle)
        
        
        self.screen.blit(image_to_draw, image_rect)
        
    #tells the computer how to make the player move
    def move(self, x_movement, y_movement):
        self.x += self.speed * x_movement
        self.y += self.speed * y_movement

#shoot function to make a WaterBaloon
    def shoot(self):
        projectile.WaterBaloon(self.screen, self.x, self.y, self.angle)