Cows and bulls game in JavaScript

Question

I've been working on this game the last 2 days. The game is working but I need a feedback for my code. Can it be made simpler? Sorry if my code is very complicated or not well written: I am in the learning process!

I feel that I could save some code and have more clear code for others to read

Gameplay looks so: you enter your guess code, computer compares it with the secret code and gives you two clues: numbers of "bulls" and "cows". What does this mean? A bull is a digit which is present in both the codes in the same position. And a cow is a digit which is present in both the codes in the different position. For example, if the secret code is 2056 and you ask 9516, an answer will be "one bull and one cow" (but you won't know which digit is a bull and which digit is a cow). That's all!

const prompt = require("prompt-sync")({ sigint: true });

// storing variables
let rulesMessage = `Gameplay looks so: you enter your guess code, computer compares it with the secret code and gives you two clues: numbers of "bulls" and "cows". What does this mean? A bull is a digit which is present in both the codes in the same position. And a cow is a digit which is present in both the codes in the different position. For example, if the secret code is 2056 and you ask 9516, an answer will be "one bull and one cow" (but you won't know which digit is a bull and which digit is a cow). That's all!`;

let cheerMessage = [
  "Just a friendly reminder that I believe in you.",
  "I predict a big win at the next guess",
  "Crossing my fingers for you! Go, go, go",
];
let level = "";
let findTheUser = prompt("what's your name: ");
askForTheRules();

//1st function generate a random number without repetitive number the length of the number is given from the user

function getRandomNumberNoRepeat(level) {
  let numberPick = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9];
  return numberPick
    .sort(() => Math.random() - 0.5)
    .join("")
    .slice(0, level);
}
// 2nd function specifies the level of the game the level value will be used in the 1st function
function levelSelector() {
  level = prompt("Choose your level easy, medium, hard or extreme: ");
  if (level.toLowerCase() === "easy") {
    level = 4;
    console.log(`\nSo easy level then guess a ${level} digit number!!Good luck ${findTheUser}`);
  } else if (level.toLowerCase() === "medium") {
    level = 6;
    console.log(`\nSo medium level then guess a ${level} digit number!!Good luck ${findTheUser}`);
  } else if (level.toLowerCase() === "hard") {
    level = 7;
    console.log(`\nSo hard level then guess a ${level} digit number!!Good luck ${findTheUser}`);
  } else if (level.toLowerCase() === "extreme") {
    level = 9;
    console.log(`\nSo extreme level then guess a ${level} digit number!!you are brave ${findTheUser}`);
  } else {
    level = false;
    console.log(
      "\nthe level should be: easy, medium, hard or extreme! check for typos!"
    );
  }
  return level;
}

// 3rd function will ask the user if knows the rules

function askForTheRules() {
  let question = prompt(`Do you know the rules of the game ${findTheUser} Y/N: `);
  console.clear();
  if (question.toUpperCase() === "N") {
    console.log(`\n${rulesMessage}\n\nLet´s go ${findTheUser}\n`);
  } else {
    console.log(`\nLet´s go ${findTheUser}`);
  }
}
// 4th function generate a random message from the array:cheerMessage
function randomMessage() {
  return cheerMessage[Math.floor(Math.random() * cheerMessage.length)];
}

// 5th function ask the user if he want to play again if not greeting message
function playAgain() {
  let playAgainTheGame = "";
  while (
    !(
      playAgainTheGame.toUpperCase() === "Y" ||
      playAgainTheGame.toUpperCase() === "N"
    )
  ) {
    playAgainTheGame = prompt("Do you want to play again? Y/N: ");
    if (playAgainTheGame.toUpperCase() === "Y") {
      return start();
    } else if (playAgainTheGame.toUpperCase() === "N") {
      console.log(`\n Thanks for playing ${findTheUser} `);
      return
    }else{
    console.log(
      `Please check the input for Y for yes and N for no,any other input is not valid `
    );}

  }
  
}

// 6th function checks for repetitive numbers in users input if it's true it will ask  again for valid number

// also it will check if the length of the secret number is the same as from the user if not it will ask again for the valid number
function validGuess(guess, randomNumberNoRepeat) {
  let noRepeatInputCheck = guess.split("").sort((a, b) => a - b);
  let hasDuplicates = false;
  for (let k = 0; k < noRepeatInputCheck.length - 1; k++) {
    if (noRepeatInputCheck[k] === noRepeatInputCheck[k + 1]) {
      hasDuplicates = true;
    }
  }
  if (hasDuplicates === true) {
    console.log("Check your number!!Remember each number should be unique");
    return false;
  }
  if (randomNumberNoRepeat.length !== guess.length) {
    console.log(`Not valid number,you need ${level} digit number!!!Let's go ${findTheUser}`);
    return false;
  }if (!/^\d+$/.test(guess)) {
    console.log(`only numbers are allowed!!!!Let's go ${findTheUser}`);
    return false
  }
  return true;
}
// 7th function  pass as parameter the level of the user every time the while loop runs it count as an attempt

function playTheGame(level) {
  let secretNumber = getRandomNumberNoRepeat(level);
  let attempts = 0;
  console.log("\n");
  while (true) {
    attempts++;
    guess = prompt("Number: ");
    // if the guess is the same number as the secretNumber then you won message will be print and also the attempts
    if (secretNumber === guess) {
      console.log(
        attempts === 1
          ? `you won at your first attempt well done ${findTheUser}`
          : `You won after ${attempts} attempts very well done ${findTheUser} `
      );
      break;
    }
    // calling the function that check for the user input if follow the rules of the game
    if (!validGuess(guess, secretNumber)) {
      continue;
    }
    // check and count the secretNumber if has same number as the users input
    // if the number is in the same position  then it will count a bull
    // if the numbers is included in the guess but in different position it will count as a cow
    let cows = 0;
    let bulls = 0;
    for (let i = 0; i < secretNumber.length; i++) {
      for (let j = 0; j < guess.length; j++) {
        if (secretNumber[i] === guess[j]) {
          if (i === j) {
            bulls++;
          } else {
            cows++;
          }
        } else continue;
      }
    }
    // if the user dont find anything then it will print a random cheer message
    if (bulls === 0 && cows === 0) {
      console.log("\n", randomMessage(), "\n");
    }
    console.log(
      cows === 1 ? `You found ${cows} cow &&` : `You found ${cows} cows &&`,
      bulls === 1 ? `You found ${bulls} bull` : `You found ${bulls} bulls `
    );
   
  }
}

// calling the functions and start the game
function start() {

  let level = levelSelector();
  while (level === false) {
    level = levelSelector();
  }
  playTheGame(level);
  playAgain();
}
start();