The first two riddles and answers can be found here: http://thinks.com/riddles/a1-riddles.htm I'm not sure if more can as well but I'll bet they can. I'm only up to the first two.
If you refresh really fast after a round, it won't have time to save and you can try again. Do so when you lose Happiness. This is about the only way to win the Harder setting.
My only problem with this fun game is that eventually you go so fast and jump so high that you can't see in front of you beyond microseconds of time. I suggest a zoom to the camera lens that you go farther and farther back as an upgrade and can then see farther and farther.