Survive The Sphinx
"Hello, young human. We just crossed paths. Well, I'll kill you now. Wait, you want to play a game of riddles? Fair enough. I shall give you nine riddles to solve."
"But remember, if you get below 60% at the end, I will eat you for lunch. But if you get over 60%, then you may go. No running away! Now that you're here, you have to do this, or you may die."