It's a neat concept! It took me a minute to figure out I needed to weigh the eggs relative to each other (Because all the eggs were lighter than the scale weight options) and see which stood out. The ruler also didn't help as they were all the same size. I like the idea of the added time pressure aswell.
There's other things you could introduce to check, like candling eggs as another way to check.
Congrats on submitting!