And please read the form guidelines about the use of code tags. Putting your message in big red characters turns people off (it did me - I just moved on!) and is considered boorish.
if(userAnswer==="yes"){
What if the user types Yes, y or Y?
But I see that your userAnswer comes from a confirm box so is true or false, not yes or no.
if(age > = 18 ){
What is the user answers "Mickey Mouse"?
var feedback=prompt("Please rate this game 1-10");
What if the user enters -10 (my evaluation, I am afraid!
)