simple pong game using pygamezero

pong.py

import pgzrun
from random import randint


WIDTH = 800
HEIGHT = 600
BLACK = (0, 0, 0)
paddle = {"x": 20, "y": HEIGHT-50, "length": 200, "width":25}
ball = {"x": 0, "y": 0, "move_x": 5, "move_y": 5}
BALL_RADIUS = 25
WHITE = (255, 255, 255)
is_game_over = False
score = 0
miss_count = 0
missed = False


def draw():
    screen.clear()
    screen.fill(BLACK)
    screen.draw.filled_circle((ball["x"], ball["y"]), BALL_RADIUS, 'red')
    screen.draw.filled_rect(Rect(paddle["x"],paddle["y"],paddle["length"],paddle["width"]),'white')
    screen.draw.text("Score: "+str(score), (10, 10), fontsize=25, color=WHITE)
    screen.draw.text("Miss: " + str(miss_count), (10, 30), fontsize=25, color=WHITE)
    draw_game_end()


def update():
    if not missed and not is_game_over:
        move_ball()
        bounce()
        detect_collision()


def move_ball():
    ball["x"] += ball["move_x"]
    ball["y"] += ball["move_y"]


def on_mouse_move(pos):
    if (pos[0] >= 0) and (pos[0] <= (WIDTH - paddle["length"])):
        paddle["x"] = pos[0]


def on_mouse_down():
    global missed
    if missed:
        missed = False
        position_ball()


def on_key_down(key):
    global is_game_over
    if is_game_over and key == keys.SPACE:
        reset()


def bounce():
    if (ball["x"] > (WIDTH - BALL_RADIUS)) or (ball["x"] < BALL_RADIUS):
        ball["move_x"] *= -1
    if ball["y"] < BALL_RADIUS:
        ball["move_y"] *= -1


def detect_collision():
    global score, miss_count, missed
    if (ball["y"] + BALL_RADIUS) > (paddle["y"]):
        if((ball["x"] + BALL_RADIUS) > paddle["x"]) and ((ball["x"]-BALL_RADIUS) <= (paddle["x"] + paddle["length"])):
            ball["move_y"] *= -1
            score = score + 1

        else:
            missed = True
            miss_count = miss_count +1
            check_game_over()


def position_ball():
    ball["x"] = randint(BALL_RADIUS, WIDTH - BALL_RADIUS)
    ball["y"] = BALL_RADIUS


def draw_game_end():
    global is_game_over
    if is_game_over:
       screen.draw.text("GAME OVER !!", (WIDTH/2, 10), fontsize=30, color=WHITE)
       screen.draw.text("Press SPACE key to start a new game", (WIDTH / 2 - 50, 30), fontsize=25, color=WHITE)
    elif missed:
        screen.draw.text("Missed it! Click to continue", (WIDTH / 3, 30), fontsize=30, color=WHITE)


def check_game_over():
    global is_game_over, miss_count
    if miss_count >= 5:
        is_game_over = True


def reset():
    global score, miss_count, missed, is_game_over
    score = 0
    miss_count = 0
    missed = False
    is_game_over = False
    position_ball()


position_ball()
pgzrun.go()