C# Number Guessing Game

Program.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text.RegularExpressions;

namespace NumberGuessingGame
{
    class Program
    {
        private const string _MIN = "minimum";
        private const string _MAX = "maximum";

        static void Main(string[] args)
        {
            Console.WriteLine("Think of a number and keep that number in your mind.");
            Console.WriteLine("Now, provide a number range, from which the program should guess to find the number you're thinking of...");
            NumberGuess.GetGuessingRangeFromUser(_MIN, 0);
            NumberGuess.GuessNumber();
            NumberGuess.CheckIfUserWantsToPlayAgain(0);
        }

        public static class NumberGuess
        {
            private static int? GuessRangeMinimum { get; set; }
            private static int? GuessRangeMaximum { get; set; }
            private static List<int> GuessRange { get; set; }
            private static List<int> GuessedNumbers { get; set; } = new List<int>();

            private const string _INVALID_INPUT_MESSAGE = "Your input is invalid. Try again";

            public static void GetGuessingRangeFromUser(string rangePosition, int attempts)
            {
                if (attempts > 0)
                    Console.WriteLine(_INVALID_INPUT_MESSAGE);
                Console.WriteLine($"Enter a whole number that is the {rangePosition} number in the range of possible numbers to guess from...");
                string response = Console.ReadLine();
                int num;
                if (Int32.TryParse(response, out num))
                {
                    if (rangePosition == _MIN)
                    {
                        GuessRangeMinimum = num;
                        GetGuessingRangeFromUser(_MAX, 0);
                    }
                    else if (rangePosition == _MAX)
                    {
                        if (num > GuessRangeMinimum)
                        {
                            GuessRangeMaximum = num + 1;
                            GuessRange = new List<int>(Enumerable.Range((int)GuessRangeMinimum, (int)GuessRangeMaximum - (int)GuessRangeMinimum));
                        }
                        else
                            GetGuessingRangeFromUser(rangePosition, ++attempts);
                    }
                }
                else
                    GetGuessingRangeFromUser(rangePosition, ++attempts);
            }

            public static void GuessNumber()
            {
                if (!AllPossibleNumbersHaveBeenGuessed())
                {
                    Random rdm = new Random();
                    int number;
                    do
                        number = rdm.Next((int)GuessRangeMinimum, (int)GuessRangeMaximum);
                    while (GuessedNumbers.Contains(number));
                    GuessedNumbers.Add(number);
                    PresentGuessToUser(number, 0);
                }
                else
                    Console.WriteLine("Well, I think you must have forgotten your number, because I've guessed all the numbers in the range that you specified.");
            }

            private static void PresentGuessToUser(int guess, int attempts)
            {
                if (attempts > 0)
                    Console.WriteLine(_INVALID_INPUT_MESSAGE);
                Console.WriteLine($"Is {guess} the number you're thinking of? (y/n)");
                string response = Console.ReadLine().ToLower();
                if(response.IsYes())
                    Console.WriteLine("Hooray! I guessed it!");
                else if (response.IsNo())
                    GuessNumber();
                else
                    PresentGuessToUser(guess, ++attempts);
            }

            private static bool AllPossibleNumbersHaveBeenGuessed() =>
                GuessedNumbers.Count == GuessRange.Count;

            public static void CheckIfUserWantsToPlayAgain(int attempts)
            {
                if (attempts > 0)
                    Console.WriteLine(_INVALID_INPUT_MESSAGE);
                Console.WriteLine("Would you like to play again? (y/n)");
                string response = Console.ReadLine().ToLower();
                if (response.IsYes())
                {
                    ResetRange();
                    Main(new string[] { });
                }
                else if (response.IsNo())
                {
                    Console.WriteLine("Thanks for playing! I hope you enjoyed it!\nPress any key to exit...");
                    Console.ReadKey();
                }
                else
                    CheckIfUserWantsToPlayAgain(++attempts);
            }

            private static void ResetRange()
            {
                GuessRangeMaximum = null;
                GuessRangeMinimum = null;
                GuessRange.Clear();
                GuessedNumbers.Clear();
            }
        }
    }

    public static class StringExtensions
    {
        public static bool IsYes(this string response) =>
            Regex.IsMatch(response, @"\b(y|yes)\b");

        public static bool IsNo(this string response) =>
            Regex.IsMatch(response, @"\b(n|no)\b");
    }
}