Laingame.net

[Plazorn]

There was a PSX game that released alongside the TV series, but it was arguably even more obscure than the series itself. Serial Experiments Lain was meant to be a mixed media project. I see the game as a sort of puzzle/audio-book/visual-novel, because you are trying to find all of the information about Lain possible (which are in video, audio, or text form depending) while navigating through confusing menus.
The folks on Laingame.net took it upon themselves to translate the game from Japanese to English, giving a whole new audience accessibility to play it. This game is playable on the website itself, or you can download it to play locally. I encourage you to try the game yourselves.