I became pi day challenge genius #181 at 3:14 on Sunday :-) Less than an estimated 10% of those who play do all 37+ (some have groups of puzzles). You can still play at any time at pidaychallenge.com #pidaychallenge Pi Day Challenge throughout the year. They're not just math/physics puzzles.
Per the owner of the site, I calculated the genius percentage incorrectly. About 10,000 people took the challenge, so becoming a “genius” is pretty rare.
One of my elementary age students this year started answering some of the hard ones even faster than I did. I don't know if he'll complete all the puzzles, but each year his lateral and creative thinking improves. Having these extra-curricular activities helps youth have FUN!!!
Try a few out... even if you think you're stuck. It's amazing what the brain can do with a good night's sleep.