There is a German Wikipedia article[0] and it's mostly readable through Google Translate[1] (I made a static snapshot).
[0] - https://de.wikipedia.org/wiki/Graal_Online
[1] - https://archive.ph/77B1o
[0] - https://de.wikipedia.org/wiki/Graal_Online
[1] - https://archive.ph/77B1o
Graal Online doesn't even have a Wikipedia article. Like there ought to be a tomb stone.