I found this on http://www.gamebrew.com. After you get to the top, Donkey Kong takes the girl and goes higher, and keeps on doing this. Is he supposed to? Also, I don’t get How High Can You Get.
Games Guru: Donkey Kong continues to take Pauline higher until you defeat him and rescue her—in the girder stage in which you knock the pins out of the steel girder building and it collapses, spilling DK on his head. Sadly, the rescue is short lived. From there you return to the barrel-jumping stage, followed by the spring factory, followed by the cement factory. As I’m sure you know, you simply continue and Jumpman (Mario’s original name in this game) never really gets the girl.
(BTW, the cement factory level, my favorite, isn’t on the NES version of Donkey Kong. Bummer.)