The Castle of the Big Red Key- BASIC was created with Inform and has IFID 42732EBE-E656-411A-A6D5-B27389E940DA. To play a work like this one, you need an interpreter program: many are available, among them Zoom
for Mac OS X and for Unix; Windows Frotz or Windows Glulxe for Windows.
Or you can play without downloading anything by following the 'Play In-Browser'
link, using the Parchment interpreter. You'll need to have Javascript enabled
on your web browser.