A 100% Walkthrough of New Super Mario Bros. DS showing off all 8 Worlds in the game with all secret exits and star coins.
New Super Mario Bros. DS Playlist: https://www.youtube.com/playlist?list=PLJY2r98E0ngJfL6umI8Hn66XQ3lxslroH
TIME STAMPS
World 1. 00:33
World 2. 22:47
World 3. 48:40
World 4. 1:16:54
World 5. 1:49:02
World 6. 2:21:54
World 7. 2:57:29
World 8. 3:38:59
Source