Speculative, original, and very well-written.
Kastrup, in this brilliant little book, tries to change our view of reality by taking consciousness as the fundamental ontological category, and develops a very interesting new perspective, that hinges on speculative science (especially particular theories combining quantum mechanics with a theory of consciousness), but it can also (in my view) not be dismissed out of hand.
He builds his case for a kind of idealism very well. I an thoroughly impressed and am still thinking about his arguments, especially after having read Thomas Nagel's "Mind and Cosmos" not so long ago.
(Nagel also wants to make consciousness into a fundamental ontological category, but develops his ideas differently from idealism, although it may be that Kastrup's ideas are compatible to Nagel's - I have to think about this a bit more.)