I absolutely love the first half of this; the 1910s explosion of ideas, of modernism and technology and psychology leading both to boundary-pushing art and medicine and the madness of war, the supercharged ideas of the 20th century given terrible purpose. Which of course is very much part of the inspiration for The Cabinet of Dr Caligari too, and I really wish the novel had built on that more. Somewhere around the middle it abandons much of that in favour of a heist plot with some sub-Pynchon meta stuff, so by the time it circles around at the end it feels a bit like it suddenly remembered that the ending has to wrap up the ideas from the beginning as well. Fun, and not a bad companion to Miéville's The Last Days of New Paris, but could have been more.

Also, jfc, get a German proofreader for your Google Translated German.