ConfettiCannon

Case:

ConfettiCannon.Fire(new ConfettiCannon.Options
{
    ParticleCount = 100,
    Spread = 70,
    Origin = new Point(0.5, 0.6)
});

//OR

var random = new Random();

ConfettiCannon.Fire(new ConfettiCannon.Options
{
    Angle = random.Next(55, 125),
    Spread = random.Next(50, 70),
    ParticleCount = random.Next(50, 100),
    Origin = new Point(0.5, 0.6)
});

//Realistic

const int count = 200;

Fire(0.25, new ConfettiCannon.Options { Spread = 26, StartVelocity = 55 });
Fire(0.2, new ConfettiCannon.Options { Spread = 60 });
Fire(0.35, new ConfettiCannon.Options { Spread = 100, Decay = 0.91, Scalar = 0.8 });
Fire(0.1, new ConfettiCannon.Options { Spread = 120, StartVelocity = 25, Decay = 0.92, Scalar = 1.2 });
Fire(0.1, new ConfettiCannon.Options { Spread = 120, StartVelocity = 45 });

return;

void Fire(double particleRatio, ConfettiCannon.Options options)
{
    options.ParticleCount = (int) Math.Floor(count * particleRatio);
    ConfettiCannon.Fire(options);
}

//Firework
const int duration = 15 * 1000;

var random = new Random();
DateTime animationEnd = DateTime.Now + TimeSpan.FromMilliseconds(duration);

var timer = new DispatcherTimer(DispatcherPriority.ApplicationIdle)
{
    Interval = TimeSpan.FromMilliseconds(250)
};

timer.Tick += OnTimerOnTick;
timer.Start();

return;

void OnTimerOnTick(object o, EventArgs _)
{
    double timeLeft = (animationEnd - DateTime.Now).TotalMilliseconds;

    if (timeLeft <= 0)
    {
        timer.Tick -= OnTimerOnTick;
        timer.Stop();
    }

    var particleCount = (int) (50 * (timeLeft / duration));
    ConfettiCannon.Fire(new ConfettiCannon.Options
    {
        StartVelocity = 30,
        Spread = 360,
        Ticks = 60,
        ParticleCount = particleCount,
        Origin = new Point
        {
            X = RandomInRange(0.1, 0.3),
            Y = random.NextDouble() - 0.2
        }
    });
    ConfettiCannon.Fire(new ConfettiCannon.Options
    {
        StartVelocity = 30,
        Spread = 360,
        Ticks = 60,
        ParticleCount = particleCount,
        Origin = new Point
        {
            X = RandomInRange(0.7, 0.9),
            Y = random.NextDouble() - 0.2
        }
    });
}

// Starts
SetTimeout(Shoot, 0);
SetTimeout(Shoot, 100);
SetTimeout(Shoot, 200);
return;

void Shoot()
{
    ConfettiCannon.Fire(new ConfettiCannon.Options
    {
        Spread = 360,
        Ticks = 50,
        Gravity = 0,
        Decay = 0.94,
        StartVelocity = 30,
        Colors = ["#FFE400", "#FFBD00", "#E89400", "#FFCA6C", "#FDFFB8"],
        ParticleCount = 40,
        Scalar = 1.2,
        Shapes = ["star"]
    });
    ConfettiCannon.Fire(new ConfettiCannon.Options
    {
        Spread = 360,
        Ticks = 50,
        Gravity = 0,
        Decay = 0.94,
        StartVelocity = 30,
        Colors = ["#FFE400", "#FFBD00", "#E89400", "#FFCA6C", "#FDFFB8"],
        ParticleCount = 10,
        Scalar = 0.75,
        Shapes = ["circle"]
    });
}

void SetTimeout(Action action, int delayMilliseconds)
{
    var timer = new DispatcherTimer { Interval = TimeSpan.FromMilliseconds(delayMilliseconds) };
    timer.Tick += OnTimerOnTick;
    timer.Start();
}

void OnTimerOnTick(object o, EventArgs _)
{
    Shoot();

    if (o is not DispatcherTimer timer)
    {
        return;
    }

    timer.Tick -= OnTimerOnTick;
    timer.Stop();
}

//Snow
const int duration = 15 * 1000;

var random = new Random();
DateTime animationEnd = DateTime.Now + TimeSpan.FromMilliseconds(duration);
double skew = 1;

new AnimationFrame().Start(_ =>
{
    double timeLeft = (animationEnd - DateTime.Now).TotalMilliseconds;

    if (timeLeft <= 0)
    {
        return true;
    }

    int ticks = (int) Math.Max(200, 500 * (timeLeft / duration));
    // ReSharper disable once AccessToModifiedClosure
    skew = Math.Max(0.8, skew - 0.001);

    ConfettiCannon.Fire(new ConfettiCannon.Options
    {
        ParticleCount = 1,
        StartVelocity = 0,
        Ticks = ticks,
        Origin = new Point
        {
            X = random.NextDouble(),
            Y = random.NextDouble() * skew - 0.2
        },
        Colors = ["#ffffff"],
        Shapes = ["circle"],
        Gravity = RandomInRange(0.4, 0.6),
        Scalar = RandomInRange(0.4, 1),
        Drift = RandomInRange(-0.4, 0.4),
    });

    return false;
});

//School Pride
const int duration = 15 * 1000;

DateTime animationEnd = DateTime.Now + TimeSpan.FromMilliseconds(duration);

new AnimationFrame().Start(_ =>
{
    double timeLeft = (animationEnd - DateTime.Now).TotalMilliseconds;
    if (timeLeft <= 0)
    {
        return true;
    }

    ConfettiCannon.Fire(new ConfettiCannon.Options
    {
        ParticleCount = 2,
        Angle = 60,
        Spread = 55,
        Origin = new Point(0, 0.5),
        Colors = ["#bb0000", "#ffffff"],
    });
    ConfettiCannon.Fire(new ConfettiCannon.Options
    {
        ParticleCount = 2,
        Angle = 120,
        Spread = 55,
        Origin = new Point(1, 0.5),
        Colors = ["#bb0000", "#ffffff"],
    });

    return false;
});

private static double RandomInRange(double min, double max)
    {
        var random = new Random();
        return random.NextDouble() * (max - min) + min;
    }

    private class AnimationFrame
    {
        private Func<double, bool> _callback;
        private long _lastTicks;

        public void Start(Func<double, bool> callback)
        {
            _callback = callback;
            _lastTicks = DateTime.Now.Ticks;
            CompositionTarget.Rendering += OnRendering;
        }

        private void OnRendering(object sender, EventArgs e)
        {
            long nowTicks = DateTime.Now.Ticks;
            double deltaTime = (nowTicks - _lastTicks) / 10000000.0;
            _lastTicks = nowTicks;

            if (_callback?.Invoke(deltaTime) == true)
            {
                CompositionTarget.Rendering -= OnRendering;
            }
        }
    }

effect: