One of the central themes of Into the Woods is that things do not work out
happily ever after. This musical, which interleaves various
Brothers Grimm fairy tales into one all-encompassing story, ends the
first act on an up note as all of the characters (the baker and his wife,
jack,
little red,
cinderella, the witch,
rapunzel) have found the things they've always most desired.
The first act ends with a glorious celebration of triumph and happiness, only to begin the second act with the words, "once upon a time, later." The second act departs from the traditonal Grimm fairy tale endings and instead takes the stories to their logical conclusions... unhappiness. The princes are unhappy with their stay-at-home lives and seek out new conquests ("I was raised to be charming, not sincere"). The baker doesn't want the responsibility of caring for a child, his wife wants a bigger home and more support. Cindarella is conflicted between staying on the path and seeking out adventure, Jack, while rich and with cow, is still without a friend or a pet, and the witch finds that her newfound beauty is nothing without power.
By the end, the characters have realized that life is not simple, there are no clear answers, and each has had a chance to reflect on his or her unique circumstances and how to proceed.
Watch this show through the first act and you have a pleasant fairy-tale retelling. Watch the second act and you have a powerful message backed by extrordinary songs. If you can't see it on Broadway, I recommend the DVD.