Observer - 1

using System;

namespace PlayBall {
    public class BallHitEventArgs : EventArgs {
        public int Speed { get; private set; }
        public int Direction { get; private set; }

        public BallHitEventArgs(int speed, int direction) {
            Speed = speed;
            Direction = direction;
        }
    }
}
//
using System;

namespace PlayBall {
    internal class BallGame {

        public event EventHandler<BallHitEventArgs> ballHit;
        public event EventHandler gameOver;

        internal void StartGame(int speed, int direction) {
            OnBallHit(speed, direction);
            OnGameOver();
        }

        private void OnGameOver() {
            Console.WriteLine("[NOTIFIER] : The game is over");
            if (gameOver == null) return;
            gameOver(this, EventArgs.Empty);
        }

        public void OnBallHit(int speed, int direction) {
            var message = "[NOTIFIER] : the ball has been hit [{0}][{1}]";
            Console.WriteLine(message, speed, direction);
            if (ballHit == null) return;
            ballHit(this, new BallHitEventArgs(speed, direction));
        }
    }
}
//
using System;

namespace PlayBall {
    internal class RadioListener {
        public RadioListener() {
        }

        internal void TunesIntoGame() {
            var ballGame = new BallGame();

            //start Observing...
            ballGame.ballHit += BallGame_ballHit;
            ballGame.gameOver += BallGame_gameOver;

            // Play the Game...
            ballGame.StartGame(20, 359);
        }
        private void BallGame_ballHit(object sender, BallHitEventArgs e) {
            var message = "[OBSERVER]: I have been told the ball has been hit [{0}][{1}]";
            Console.WriteLine(message, e.Speed, e.Direction);
        }
        private void BallGame_gameOver(object sender, EventArgs e) {
            Console.WriteLine("[OBSERVER]: I have been told the game is over");
        }
    }
}
//
using System;

namespace PlayBall {
    public class Program {

        public static void Main() {
            var p = new Program();
            p.RunTheTest();
        }
        private void RunTheTest() {

            var radioListener = new RadioListener();
            radioListener.TunesIntoGame();

            Console.WriteLine("That's all for now - press return twice");
            Console.Read();
        }
    }
}
//