Challenge — Make Your Game Feel "Juicy"

By the end of this lesson you can:

• Apply screen shake, hit flash, and particle bursts to a game simultaneously without breaking its existing logic.
• Use sounds.x.play() to add audio feedback on key events (hit, score milestone, death).
• Explain in one sentence why each "juicy" effect makes the game feel better.

Before the timer starts, answer these three questions — no looking at notes. Write them on paper or say them aloud to a partner.

1. How many variables do you need for screen shake, and what do they do?
2. What makes a hit-flash fade away automatically?
3. In which function do you add a new particle to the list?

Game developers call this "juice" — the layer of sensory detail that makes interactions feel weighty. Here is the checklist you will use during the timed challenge.

Screen shake

shake_timer = 0
ox, oy = 0, 0

def trigger_shake(frames=14):
    global shake_timer
    shake_timer = frames

# in update():
if shake_timer > 0:
    shake_timer -= 1
    ox, oy = random.randint(-7, 7), random.randint(-7, 7)
else:
    ox, oy = 0, 0

Hit flash

flash_timer = 0

def trigger_flash(frames=8):
    global flash_timer
    flash_timer = frames

# in update():
if flash_timer > 0:
    flash_timer -= 1

# in draw() after the sprite:
if flash_timer > 0:
    r = Rect((sprite.x - 28, sprite.y - 28), (56, 56))
    screen.draw.filled_rect(r, (255, 255, 255))

Particle burst

particles = []

def spawn_burst(cx, cy, count=12):
    for _ in range(count):
        particles.append({
            "x": cx, "y": cy,
            "vx": random.uniform(-4, 4),
            "vy": random.uniform(-5, 1),
            "life": random.randint(10, 20),
        })

# in update():
for p in particles:
    p["x"] += p["vx"]
    p["y"] += p["vy"]
    p["life"] -= 1
particles[:] = [p for p in particles if p["life"] > 0]

Sound feedback

# Place hit.wav in a sounds/ folder next to your script, then:
sounds.hit.play()   # on hit event

# For a score milestone:
if score % 5 == 0:
    sounds.fanfare.play()

Before — plain catcher (no juice)

# plain_catcher.py — no juice
import pgzrun
import random

WIDTH = 480
HEIGHT = 320
ball_x = 240
ball_y = -30
score = 0

def update():
    global ball_y, ball_x
    ball_y += 4
    if ball_y > HEIGHT + 30:
        ball_y = -30
        ball_x = random.randint(30, WIDTH - 30)

def on_mouse_down(pos, button):
    global score, ball_y, ball_x
    dist = ((pos[0]-ball_x)**2 + (pos[1]-ball_y)**2)**0.5
    if dist < 28:
        score += 1
        ball_y = -30
        ball_x = random.randint(30, WIDTH - 30)

def draw():
    screen.fill("black")
    screen.draw.filled_circle((ball_x, ball_y), 26, "crimson")
    screen.draw.text(f"Score:{score}", topleft=(10,10),
                     fontsize=22, color="white")

pgzrun.go()

After — juiced catcher (shake + flash + particles)

# juicy_catcher.py — fully juiced
import pgzrun
import random

WIDTH = 480
HEIGHT = 320
ball_x, ball_y = 240, -30
score = 0
shake_timer = 0
flash_timer = 0
ox, oy = 0, 0
particles = []

def spawn_burst(cx, cy):
    for _ in range(14):
        particles.append({
            "x": cx, "y": cy,
            "vx": random.uniform(-5, 5),
            "vy": random.uniform(-6, 1),
            "life": random.randint(8, 18),
        })

def update():
    global ball_y, ball_x, shake_timer, flash_timer, ox, oy
    ball_y += 4
    if ball_y > HEIGHT + 30:
        ball_y = -30
        ball_x = random.randint(30, WIDTH - 30)
    if shake_timer > 0:
        shake_timer -= 1
        ox, oy = random.randint(-7, 7), random.randint(-7, 7)
    else:
        ox, oy = 0, 0
    if flash_timer > 0:
        flash_timer -= 1
    for p in particles:
        p["x"] += p["vx"]
        p["y"] += p["vy"]
        p["life"] -= 1
    particles[:] = [p for p in particles if p["life"] > 0]

def on_mouse_down(pos, button):
    global score, ball_y, ball_x, shake_timer, flash_timer
    dist = ((pos[0]-ball_x)**2 + (pos[1]-ball_y)**2)**0.5
    if dist < 28:
        score += 1
        spawn_burst(ball_x, ball_y)
        shake_timer = 14
        flash_timer = 8
        ball_y = -30
        ball_x = random.randint(30, WIDTH - 30)

def draw():
    screen.fill("black")
    bx, by = ball_x + ox, ball_y + oy
    screen.draw.filled_circle((bx, by), 26, "crimson")
    if flash_timer > 0:
        r = Rect((bx-28, by-28), (56, 56))
        screen.draw.filled_rect(r, (255, 255, 255))
    for p in particles:
        alpha = max(0, p["life"] * 13)
        screen.draw.filled_circle(
            (int(p["x"] + ox), int(p["y"] + oy)), 4, (255, 200, 0))
    screen.draw.text(f"Score:{score}", topleft=(10,10),
                     fontsize=22, color="white")

pgzrun.go()

"Juice" is not one trick — it is a stack of small, cheap effects that fire together on impact: screen shake, hit flash, and a particle burst. Each effect follows the same pattern: a timer you count down in update() and a drawing call you guard with an if timer > 0 check in draw(). Stacking them makes every action feel powerful without changing the actual game rules.