I used to play Portal on my Commodore 64 as a child. It was a unique game. There were 12 different dataspaces that the player navigated between in order to expose the story.
You play a space traveler who has returned to an empty Earth after being away for decades. This was the perfect game for a lonely only child to play. The game was all mental, took a long time to play, and involved doing a lot of reading.
Apparently, it was set up so that eventually you would "win", no matter what, but it didn't really seem that way. You had to navigate to the right dataspaces in order to unlock new information at other dataspaces.
Anyway, I'm about to read this website for a little bit.