I've just finished playing the on-line game of "Yeti Vision" (in which you have to stop the roller-coaster train and save the mountain from the Yeti [all inspired by DisneyWorlds new ride "Expedition Everest"
http://www.disneyeverest.com ]).
It reminded me that I used to play some great adventure games on my Commodore Vic20 - mainly written by Scott Adams.
Are there any good on-line or downloadable adventures for the PC - or has that genre died a gentle death?