The good:
- Great idea - a message from the stars
- a major installement of Mr Lem's theme: we incorrectly think of aliens as psycologically human.
- enjoyable to read
- lots of other good ideas along the way


The not so good:
- too much philosophy, a too low philosophy:action ratios.
- to me, it just kinda finished. "Oh, that's the end?". Yes, our hero had understood something, but there was really much more.

This book reminded me a lot of Solaris. Where Solaris had chapters about the academic history of the study of the sea, this had philosophizing.