particles

import pygame, random

pygame.init()
clock = pygame.time.Clock()
WIDTH = 800
HEIGHT = 600
screen = pygame.display.set_mode((WIDTH, HEIGHT))

particles = []

# Creating a semi-transparent surface to create fade-effect.
bg = pygame.Surface((WIDTH,HEIGHT))
bg.set_alpha(70)
bg.fill((0,0,0))

class Particle():
    def __init__(self,x,y):
        self.x = x
        self.y = y
        self.speed_x = random.randint(-12,12)
        self.speed_y = random.randint(-12,2)
        self.life = random.randint(3,9)
        self.farge = 255

    def update(self):
        self.x += self.speed_x
        self.y += self.speed_y
        self.speed_y += 0.5
        self.life -= 0.5
        self.farge -= 7

        if self.x > WIDTH or self.x < 0: self.speed_x *= -1

        if self.y > HEIGHT: self.speed_y *= -1

        if self.life < 1:
            particles.remove(self)
            del self

    def draw(self):
        pygame.draw.circle(screen,(255,self.farge,0),(int(self.x),int(self.y)),int(self.life))
# END OF PARTICLE CLASS

def explotion(mx,my):
    for i in range(60):
        minPartikkel = Particle(mx,my)
        particles.insert(0,minPartikkel)

while True:
    screen.blit(bg,(0,0))
    for particle in particles[::-1]:
        particle.update()
        particle.draw()

    clock.tick(30)
    pygame.display.update()

    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False

        # create explotion everywhere the mouse moves
        if event.type == pygame.MOUSEMOTION:
            mx,my = pygame.mouse.get_pos()
            explotion(mx,my)
pygame.quit()