I'd like some critique and suggestions for improvement on my Quiz game please.

/*The Quiz Game
Answer five questions 
Win a prize
By Joe Worthington
*/

//Welcomes player, asks for name and then displays the the ranking

var player = prompt("Hello and welcome to The Quiz Game. Here are 5 questions to answer. Let's begin with your name?");

document.write("<p>" + player + " here is what you can win:</p>" + "<p>5 correct answers = GOLD badge</p>" + "<p>3-4 correct answers = SILVER badge</p>"  + "<p>1-2 correct answers = BRONZE badge</p>" + "<p>0 correct answers = THE DUNCE'S HAT</p>");

//Question 1
var playerAnswer1 = prompt("Question 1. Who wrote The New York Trilogy?");
var answer1 = "paul auster".toUpperCase() ;
if (playerAnswer1.toUpperCase() === answer1) {
  var score = 1;
} else (score = 0); {
  document.write("<p>Your answer was " + playerAnswer1 + "</p>");
}
//Prints score to console log
console.log(score);

//Question 2
var playerAnswer2 = prompt("Question 2. What artist painted the picture Guernica?");
var answer2 = "picasso".toUpperCase();
if (playerAnswer2.toUpperCase() === answer2) {
  score = score + 1;
} else ( score + 0); {
  document.write("<p>Your answer was " + playerAnswer2) + "</p>";
}

//Prints score to console log
console.log(score);

//Question 3
var playerAnswer3 = prompt("Question 3. What is 10% of 35?");
var answer3 = 3.5;
if (parseFloat(playerAnswer3) === answer3) {
  score = score + 1;
} else (score + 0); {
  document.write("<p>Your answer was " + playerAnswer3 + "</p>");
}

//Prints score to console log
console.log(score);

//Question 4
//Assumes the answer is false
var correctAnswer4 = false
//Generates the random number I'm thinking of between 1-10
var randomNumber = Math.floor(Math.random() * 10) +1;
/*User has first attempt with the following results:
1.Guess it right first time and it writes the guess to the document
2.Second attempt with a hint as to the random number being higher or lower
3. Prints the second attempt to the document
*/
var playerAnswer4 = prompt("Question 4. What number am I thinking of between 1-10? (it's okay, you get two attempts!)");
if (parseInt(playerAnswer4) === randomNumber ) {
  correctGuess = true;
  score = score + 1;
  document.write("<p>Your answer was " + playerAnswer4 + ", right first time, you lucky son-of-a-gun!");
} else if (parseInt(playerAnswer4) < randomNumber) {
  var guessMore = prompt('Try again. The number I was thinking of is more than ' + playerAnswer4);
  if (parseInt(guessMore) === randomNumber) {
  correctAnswer4 = true;
    score = score + 1;
    document.write("<p>Your first guess was " + guessMore);
  } else (score + 0); {
    document.write("<p>Your second guess was " + guessMore);
  }
} else if ( parseInt(playerAnswer4) > randomNumber) {
  var guessLess = prompt('Try again. The number I was thinking of is less than '+ playerAnswer4);
  if (parseInt(guessLess) === randomNumber) {
  correctAnswer4 = true;
    score = score + 1;
    document.write("<p>Your first guess was " + guessLess);
  } else (score + 0); {
    document.write("<p>Your second guess was " + guessLess);
  }
}

//Prints score to console log
console.log(score);

//Question 5
var playerAnswer5 = prompt("Danny's mother has four children...Jimmy, Jason and Rachel... and what's the name of the fourth child?");
var answer5 = "danny".toUpperCase();
if (playerAnswer5.toUpperCase() === answer5) {
  score = score + 1;
} else (score + 0); {
  document.write("<p>Your answer was " + playerAnswer5);
}

//Prints score to console log
console.log(score);

alert("So, how did you do? Let's find out.");
if (score === 5) {
  document.write("<h1>You scored " + score + "! You won a GOLD badge! Congratulations " + player + ".</h1>");
} else if (score === 4 || score === 3) {
  document.write("<h2>You scored " + score + "! You won a SILVER badge! Well done " + player + ".</h2>");
} else if (score === 2 || score === 1) {
  document.write("<h3>You scored " + score + "! You won a BRONZE badge! Not bad " + player + ".</h3>");
} else (document.write("<h4>Your score was " + score + ". Hm, " + player + " you're going to have to wear THE DUNCE'S HAT. Maybe give it another go, hey!</h4>")); {
}

//Prints score to console log
console.log(score);