Casual games are hugely popular but underrated. Think Solitare or Mind Sweeper, if you owned a desktop computer in your life. But studies show they are "anything but casual." They are an escape from a hectic day, a way to relax and decompress without the pressures of everything else in your life.
I used to play "Bejewled" while listening to "This American Life" to relax. Now I knit while listening to "Stash and Burn" and "Knit Science." And it feels so good. Knitting is what I do to relax. and it makes me feel good. It is my casual game.