Capstone Part 1 — Plan & Build Your Arcade Game

By the end of this lesson you can:

• Complete a one-page game design: genre, controls, win/lose condition, and scoring plan.
• Build a playable prototype skeleton — a window, a player that moves, and one core mechanic running inside a four-state machine.
• Identify which polish features (particles, shake, sound) you will add in Part 2.

You have 48 lessons of Pygame Zero skills. Today you pick one idea and build it. Here are five genres that work well with the tools you have:

Choose one, or invent your own. Write it down — you will refer to it during the build.

Professional game developers write a Game Design Document (GDD). For a 30-minute game jam it becomes a one-page design. Fill in these five fields before writing a single line of code:

Your design template

What your prototype must have

• A window with WIDTH, HEIGHT, and TITLE set.
• A player that responds to input and moves on screen.
• One mechanic working: the thing that makes it a game (falling objects, bullets, enemies).
• A four-state machine: title, play, pause, game-over — even if the title screen is just text.
• Score and lives visible on screen during play.

No particles, no sound, no shake yet — those are Part 2. Today is about the game being playable.

The story

Aiman decides to build “Roti Canai Rain” — a catcher where roti canai falls from the sky and the player moves a tray left and right to catch it. Here is the complete prototype scaffold.

# roti_rain.py — capstone prototype (Part 1)
import pgzrun
import random

WIDTH = 480
HEIGHT = 320
TITLE = "Roti Canai Rain"

# --- game globals ---
state = "title"
score = 0
lives = 3
tray_x = 240
TRAY_Y = 290
TRAY_W = 70
roti_x = 240
roti_y = -30
ROTI_SPEED = 4

def reset_game():
    global score, lives, tray_x, roti_x, roti_y
    score = 0
    lives = 3
    tray_x = 240
    roti_x = random.randint(30, WIDTH - 30)
    roti_y = -30

def update_play():
    global roti_y, roti_x, lives, state
    # move tray
    if keyboard.left and tray_x > TRAY_W // 2 + 5:
        tray_x -= 5
    if keyboard.right and tray_x < WIDTH - TRAY_W // 2 - 5:
        tray_x += 5
    # move roti
    roti_y += ROTI_SPEED
    # catch check
    if (abs(roti_x - tray_x) < TRAY_W // 2 + 14
            and abs(roti_y - TRAY_Y) < 20):
        global score
        score += 1
        roti_x = random.randint(30, WIDTH - 30)
        roti_y = -30
    # miss check
    elif roti_y > HEIGHT + 30:
        lives -= 1
        roti_x = random.randint(30, WIDTH - 30)
        roti_y = -30
        if lives <= 0:
            state = "game_over"

def on_key_down(key):
    global state
    if state == "title" and key == keys.SPACE:
        reset_game()
        state = "play"
    elif state == "play" and key == keys.P:
        state = "pause"
    elif state == "pause" and key == keys.P:
        state = "play"
    elif state == "game_over" and key == keys.R:
        state = "title"

def draw_title():
    screen.draw.text("ROTI CANAI RAIN", center=(240, 120),
                     fontsize=44, color="gold")
    screen.draw.text("LEFT / RIGHT to move tray",
                     center=(240, 175), fontsize=20, color="white")
    screen.draw.text("Press SPACE to start",
                     center=(240, 205), fontsize=20, color="grey")

def draw_play():
    # tray
    tray_r = Rect((tray_x - TRAY_W//2, TRAY_Y - 8), (TRAY_W, 16))
    screen.draw.filled_rect(tray_r, (180, 120, 60))
    # roti
    screen.draw.filled_circle((roti_x, int(roti_y)), 20, "wheat")
    screen.draw.text(f"Score:{score}  Lives:{lives}",
                     topleft=(10, 10), fontsize=22, color="white")

def draw_pause_overlay():
    screen.draw.text("PAUSED — press P to resume",
                     center=(240, 160), fontsize=28, color="white")

def draw_game_over():
    screen.draw.text("GAME OVER", center=(240, 110),
                     fontsize=48, color="crimson")
    screen.draw.text(f"Score: {score}", center=(240, 175),
                     fontsize=30, color="white")
    screen.draw.text("Press R to return to title",
                     center=(240, 220), fontsize=20, color="grey")

def update():
    if state == "play":
        update_play()

def draw():
    screen.fill("black")
    if state == "title":
        draw_title()
    elif state == "play":
        draw_play()
    elif state == "pause":
        draw_play()
        draw_pause_overlay()
    elif state == "game_over":
        draw_game_over()

pgzrun.go()

A good prototype does the minimum needed to prove the game is fun: a moving player, one mechanic, score and lives, and a four-state machine so you can start and restart cleanly. Write the design template first — it keeps you focused. Polish (particles, shake, sound) comes in Part 2.