ds games winrar

HI all, how come when I unzip some games they appear on my card and are playable, and other games just show up as a folder and I cant view these when I turn on the 3ds, please help I need to do these as xmas presents for my girls.
madagascar 3 6067 and phineas and ferb 5889 are 2 of the games.

Err, some of the files are in folders, you got to find the .nds file and put that on your memory card, not the entire folder.

yeah got it, thanks for the help ;)