To give a bit of credit to the book (hints of a spoiler ahead), the aliens were different from humans in a few ways, so it made a little more sense than what someone might think from your description.

But yes, "contrived" is a great term for a lot of it. I loved the descriptions of how humans would react to aliens and in the future, the build up was amazing (or maybe I hyped it up in my head), but I felt like some of the physics got a little unbelievable, and I did not find the ending satisfying.

Overall I'd recommend it though. I had meant to read it for years, then accidentally read the 2nd book (Dark Forest) and got hooked because of the first few pages, which explains the "differences" that I'm referring to above.