At night, when it’s dark, you can only see silhouettes, so the “night” side of each challenge only gives you the outline of what you have to create. 24 "day" and 24 "night" challenges.
Just as night follows day, the "day"challenges (1-24) provide a great start that gradually builds up to the more advanced "night" challenges (25-48).
This makes "Day & Night" an educational game for children aged from 18 months to 5 years.