Module2_3_BonusTask.cs

using System;

namespace ConsoleApp
{
    internal class Program
    {
        // Смотрю есть горячий спор по именованию констант. Майкрософт рекомендует
        // использовать PascalCase, но в этом случае можно путать с методами и property.
        // Коммьюнити, судя по интернетам, предпочитает использовать UPPER_CASE. Мне кстати
        // такой подход тоже нравится. Сразу видно, что это константа.
        private const int BOARD_ROWS = 3;
        private const int BOARD_COLUMNS = 4;
        private const int MAX_ATTEMPTS = 6;
        private const int WIN_CONDITION = 3;

        private const char TRUE_SYMBOL = 'X';
        private const char FALSE_SYMBOL = 'O';

        static void Main(string[] args)
        {
            bool[] board = new bool[BOARD_ROWS * BOARD_COLUMNS];

            for (int i = 0; i < board.Length; i++)
            {
                board[i] = false;
            }

            int currentAttempt = 0;
            int currentWins = 0;

            Random random = new Random();

            while (true)
            {
                if (currentWins == WIN_CONDITION)
                {
                    Console.WriteLine("Вы выиграли игру!");
                    break;
                }

                if (currentAttempt == MAX_ATTEMPTS)
                {
                    Console.WriteLine("Вы проиграли игру. Попытки закончились!");
                    break;
                }

                Console.WriteLine($"Попытка: {currentAttempt} / {MAX_ATTEMPTS}");
                Console.WriteLine($"Победы: {currentWins} / {WIN_CONDITION}");
                Console.WriteLine("Текущее состояние поля: ");

                for (int i = 0; i < board.Length; i++)
                {
                    if (i % BOARD_COLUMNS == 0)
                    {
                        Console.WriteLine();
                    }

                    if (board[i] == true)
                    {
                        Console.Write(TRUE_SYMBOL);
                    }
                    else
                    {
                        Console.Write(FALSE_SYMBOL);
                    }
                }

                Console.WriteLine("\n");

                // Составляем список свободных (false) индексов
                int freeCount = 0;
                for (int i = 0; i < board.Length; i++)
                {
                    if (board[i] == false)
                    {
                        freeCount++;
                    }
                }

                if (freeCount == 0)
                {
                    Console.WriteLine("Все клетки заполнены. Игра завершена!");
                    break;
                }

                int[] freeIndexes = new int[freeCount];
                int indexCounter = 0;

                for (int i = 0; i < board.Length; i++)
                {
                    if (board[i] == false)
                    {
                        freeIndexes[indexCounter] = i;
                        indexCounter++;
                    }
                }

                int randomIndex = freeIndexes[random.Next(0, freeIndexes.Length)];
                board[randomIndex] = true;

                int row = randomIndex / BOARD_COLUMNS;
                int col = randomIndex % BOARD_COLUMNS;

                Console.WriteLine("Введите номер строки (1-" + BOARD_ROWS + "): ");
                int guessRow;
                while (!int.TryParse(Console.ReadLine(), out guessRow) || guessRow < 1 || guessRow > BOARD_ROWS)
                {
                    Console.WriteLine($"Некорректный ввод. Введите число от 1 до {BOARD_ROWS}.");
                }

                Console.WriteLine();

                Console.WriteLine("Введите номер столбца (1-" + BOARD_COLUMNS + "): ");
                int guessColumn;
                while (!int.TryParse(Console.ReadLine(), out guessColumn) || guessColumn < 1 || guessColumn > BOARD_COLUMNS)
                {
                    Console.WriteLine($"Некорректный ввод. Введите число от 1 до {BOARD_COLUMNS}.");
                }

                Console.WriteLine();

                currentAttempt++;

                bool isWinMatch = (guessRow == row + 1 && guessColumn == col + 1);

                if (isWinMatch)
                {
                    currentWins++;
                    Console.WriteLine("Вы угадали верно!\n");
                }
                else
                {
                    Console.WriteLine("Увы, вы не угадали. Попробуйте снова.\n");
                }
            }

            Console.WriteLine("Игра окончена. Нажмите любую клавишу для выхода...");
            Console.ReadKey();
        }
    }
}

Module2_3_Task1.cs

namespace ConsoleApp
{
    internal class Program
    {
        static void Main(string[] args)
        {
            const string commandRestart = "restart";
            const string commandPrintResult = "=";
            const string commandExit = "exit";

            int[] currentNumbers = new int[0];

            Console.BackgroundColor = ConsoleColor.Blue;
            Console.ForegroundColor = ConsoleColor.White;

            Console.WriteLine("This program counts sum all numbers entered");

            Console.BackgroundColor = ConsoleColor.Black;
            Console.WriteLine();
            Console.WriteLine("Enter first number or command:");

            Console.BackgroundColor = ConsoleColor.DarkBlue;
            Console.WriteLine("Command list");
            Console.WriteLine($"  {commandRestart} - Reset numbers");
            Console.WriteLine($"  {commandPrintResult} - Print result");
            Console.WriteLine($"  {commandExit} - Exit");
            Console.BackgroundColor = ConsoleColor.Black;
            Console.ForegroundColor = ConsoleColor.Gray;

            Console.WriteLine();
            Console.WriteLine("Enter first number or command:");

            while(true)
            {
                string commandOrNumber = Console.ReadLine() ?? string.Empty;

                if (int.TryParse(commandOrNumber, out int number))
                {
                    Array.Resize(ref currentNumbers, currentNumbers.Length + 1);
                    currentNumbers[currentNumbers.Length - 1] = number;
                    Console.WriteLine($"Number {number} added");
                    Console.WriteLine($"Total numbers: {currentNumbers.Length}");
                }
                else
                {
                    string command = commandOrNumber.ToLower();

                    switch (command)
                    {
                        case commandRestart:
                            Console.WriteLine("Numbers have been flushed");
                            currentNumbers = new int[0];
                            break;
                        case commandPrintResult:
                            if (currentNumbers.Length == 0)
                            {
                                Console.WriteLine("No numbers entered");
                            }
                            else
                            {
                                int sum = 0;
                                foreach (int n in currentNumbers)
                                {
                                    sum += n;
                                }

                                Console.WriteLine($"Result: {sum}");
                            }
                            break;
                        case commandExit:
                            Console.WriteLine("Exiting...");
                            return;
                        default:
                            Console.WriteLine("Unknown command");
                            break;
                    }
                }
            }
        }
    }
}

Module2_3_Task2.cs

namespace ConsoleApp
{
    internal class Program
    {
        static void Main(string[] args)
        {
            const int maxArrayLength = 100;
            const int minNumberInArray = 10;
            const int maxNumberInArray = 20;

            var random = new Random();
            var length = random.Next(1, maxArrayLength + 1);
            var array = new int[length];

            for (var i = 0; i < length; i++)
            {
                array[i] = random.Next(minNumberInArray, maxNumberInArray + 1);
            }

            Console.WriteLine("Array: " + string.Join(", ", array));
        }
    }
}

Module2_3_Task3.cs

namespace ConsoleApp
{
    internal class Program
    {
        static void Main(string[] args)
        {
            int[][] arr = new int[][]
            {
                new int[] { 8, 2, 3, 1, 1 },
                new int[] { 4, 12, 6, 2 },
                new int[] { 7, 8, 9 },
                new int[] { 2, 1, 10, 1},
            };

            int largerstNumber = 0;
            int[] largerstNumberPosition = new int[2];

            for(int i = 0; i < arr.Length; i++)
            {
                for(int j = 0; j < arr[i].Length; j++)
                {
                    if(arr[i][j] > largerstNumber)
                    {
                        largerstNumber = arr[i][j];
                        largerstNumberPosition[0] = i;
                        largerstNumberPosition[1] = j;
                    }
                }
            }

            Console.WriteLine($"Largest number is {largerstNumber} at position {largerstNumberPosition[0]},{largerstNumberPosition[1]}");
        }
    }
}

Module2_3_Task4.cs

namespace ConsoleApp
{
    internal class Program
    {
        static void Main(string[] args)
        {
            const string commandHead = "head";
            const string commandTail = "tail";
            const string commandExit = "exit";

            Console.BackgroundColor = ConsoleColor.White;
            Console.ForegroundColor = ConsoleColor.Black;
            // Commands list
            Console.WriteLine("Heads to Tails");
            Console.WriteLine("Are you lucky?");
            Console.WriteLine("Commands: ");
            Console.WriteLine("head - Heads");
            Console.WriteLine("tail - Tails");
            Console.WriteLine("exit - Exit");

            Console.BackgroundColor = ConsoleColor.Black;
            Console.ForegroundColor = ConsoleColor.White;
            Console.WriteLine();

            Console.WriteLine("Enter a command: ");

            var command = "";
            do
            {
                command = Console.ReadLine();

                var randomResult = new Random().Next(0, 2);

                if (command == commandHead && randomResult == 0)
                {
                    Console.WriteLine("You win!");
                    
                }
                else if (command == commandTail && randomResult == 1)
                {
                    Console.WriteLine("You win!");
                }
                else
                {
                    Console.WriteLine("You lose!");
                }
            }
            while (command != commandExit);
        }
    }
}