Who or what is KG? And where can I get more of it?
I know very little German and even less French. If you are fluent in either language, then you can make headway on your online KG research. As for me, I have difficulty finding out who/what KG is and how many releases he/they had made. There is only one thing than I know, and that is that Passage Secret is a damn fine album. What kind of music is it? The most accurate way I can put it is instrumental rock, but that traps one's preconceptions in the "post-rock" genre.
No, for this, you need to open that concept up a bit. Throw in a drum machine. Carry the sound quality to the lo-fi side of the field, but not too lo-fi. Balance the rush of growling, processed guitars with glowing synthesizers. Put some jangle here, some white noise there and mix in a few vague vocals (even if they were sung in English, I don't think I could have detected the lyrics anyway because they're so subtly mixed). KG's Passage Secret is a classic case-in-point of why people gravitate towards DIY recordings -- because the sky's the limit. There's no excuse to not be creative.