I didn't get how to win :( I saw you can go faster for 4 each time or slower for 6, but I didn't get what I shall choose in what situations. I also didn't get what hearts do.
I had the same issue, but I think I saw a dialogue box pop up and then disappear before displaying any text. As I learned myself, tweens (the things that let things fade in and out or transition from one position from another smoothly without having to make an animation track) can be a real bitch to use just how the engine wants you to so it won't cause that kind of problem.