Answer:
I'm white, I'm round, but not always around. Sometimes you see me, sometimes you don't.
Used left or right, I get to travel over cobblestone or gravel. Used up, I vie for sweet success, used down, I cause men great duress.
A precious stone, as clear as diamond. Seek it out while the sun's near the horizon. Though you can walk on water with its power, try to keep it, and it'll vanish in an hour.
What has three ways out and just one way in?
I bubble and laugh and spit water in your face. I am no lady, and I don't wear lace.
What sphinxes employ and players enjoy.
Difficult
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?