Why does my sprite player move faster when I move the mouse? I'm trying to develop a simple game made with Pygame (Python library). I have a sprite object which's the player and I move it using arrow keys. If I don't move the mouse, the sprite moves normally, but when I move the mouse, the sprite moves faster (like x2 or x3). The player object is inside the charsGroup var. I've run the game in W7 and in Ubuntu. Same thing happens in both OS. I have more entities which move like NPCs and bullets but they don't get affected, just the player. Given this, I think that the problem maybe has a direct connection with the player moving system (arrow keys). Here is the update() method of the player object def update(self) for event in pygame.event.get() key pygame.key.get pressed() mouseX, mouseY pygame.mouse.get pos() if event.type pygame.MOUSEBUTTONDOWN self.bulletsGroup.add(Bullet(pygame.image.load("bullet.png"), self.rect.x (self.image.get width() 2), self.rect.y (self.image.get height() 2), mouseX, mouseY, 50, 50)) if key pygame.K RIGHT if not self.checkCollision() self.rect.x 10 else self.rect.x 10 if key pygame.K LEFT if not self.checkCollision() self.rect.x 10 else self.rect.x 10 if key pygame.K UP if not self.checkCollision() self.rect.y 10 else self.rect.y 10 if key pygame.K DOWN if not self.checkCollision() self.rect.y 10 else self.rect.y 10 And here is the while loop while True if PLAYER.healthBase lt 0 GAMEOVER True if not GAMEOVER mapTilesGroup.draw(SCREEN) charsGroup.update() charsGroup.draw(SCREEN) npcsGroup.update() npcsGroup.draw(SCREEN) drawBullets() for event in pygame.event.get() if event.type pygame.QUIT pygame.quit() sys.exit() if GAMEOVER myfont pygame.font.SysFont("monospace", 30) label myfont.render("GAME OVER!", 1, (255, 255, 0)) SCREEN.blit(label, (400, 300)) freq.tick(0) pygame.display.flip() I don't know what more you can need to help me, but anything you need (more info or code) just ask for it!