JSFiddle - React, Tailwind, and code Playground

JavaScript

//A better code for hansi ;)
function start(){
    confirm("Are you ready to play!");
    age();
}

function startRace(){
    race();
}

function startAge(){
    age();
}

function startFeedback(){
    feedback();
}

function age(){
    var age = prompt("What's your age");
    if(parseInt(age).toString() === "NaN"){
        alert("ERROR: Not a number");
        startAge();
    }else{
        if(age < 13){
            confirm("you are allowed to play but i do not take any responsibility");
        }else{
            confirm("Good luck on your adventure");
        }
    }
    startRace();
}
function race(){
    confirm("You are at a Justin Bieber concert, and you hear this lyric 'Lace my shoes off, start racing.'");
    confirm("Suddenly, Bieber stops and says, 'Who wants to race me?'");
    var userAnswer = prompt("Do you want to race Bieber on stage?");
    if(userAnswer.toLowerCase() === "yes"){
        confirm("You and Bieber start racing. It's neck and neck! You win by a shoelace!");
        startFeedback();
    }else if(userAnswer.toLowerCase() === "no"){
        confirm("Oh no! Bieber shakes his head and sings 'I set a pace, so I can race without pacing.'");
        startFeedback();
    }else if (userAnswer.toLowerCase() === "secret"){
        confirm("Secret :D");
        startRace();
    }else{
        confirm("ERROR: Unexpected Input ");
        startRace();
    }
}
function feedback(){
    var feedback = prompt("Rate the game from 0-10");
    if(parseInt(feedback).toString() === "NaN"){
        alert("ERROR: Not a number");
        startFeedback();
    }else{
        if(feedback >= 8){
            confirm("Thank you! We should race at the next concert");
        }else{
            confirm("I'll keep practicing coding and racing.");
        }
    }
}
start();