Ajit Monteiro says: "At the BBC they have the Hitchhikers Guide To The Galaxy, Infocom game from 1984, written by Douglas Adams. Its a text based adventure game, reminiscent of games from way back when. The two episode game works pretty well even ported to flash."
In the '80s, I spent many hours playing this game. It was a lot of fun, but I got stuck (I think I was trying to convince the depressed robot to open a spaceship door for me) and never finished it. The BBC version I'm playing comes with graphics (created by people who entered a BBC contest to port the game to Flash), which might make it a little easier to solve the puzzles this time around. Link
