puzzle stumper

["KATHY NESS TT_DB User bin cdrom dev devices etc export ftp home kernel lib lost+found mnt net opt platform proc sbin tmp usr var vol xfn Children's Services TT_DB User bin cdrom dev devices etc export ftp home kernel lib lost+found mnt net opt platform proc sbin tmp usr var vol xfn Northfield"]

Hi!  Does anyone out there remember a book about:

        a boy who gets trapped on a board game
        to move to the next square he must answer a question/word puzzle
        he is helped by an angel disguised as a devil
        one question has to do with a roller coaster

the patron read it in the early 1980s.  He remembers it was about 300 pages
and had some illustrations.  Please let me know if any of this rings a bell
with you!

thanks!  Kathy Ness
         Northfield Public Library
         Northfield, Minnesota
         KathyN@SELCO.lib.mn.us