How to make a game in 48 hours

I came across a time lapse video of a game making process for Ludum Dare, the name of which is Dream Fishing. For those who don't know it, Ludum Dare is a game making competition where developers must create a game in 48 hours. As you can see, the game author, Sophie Houlden, only took breaks to eat, have some short naps and watch some Anime.