TL;DR: 6.5/10. Great start, excellent adventure, great humor (mostly concentrated in the first half of the book), very well written, but an unrealistic and much weaker ending.
Human is a real bipedal life form of midrange intelligence, living a largely deluded existence on a small, waterlogged planet in a very lonely corner of the universe.
Don't ever be afraid of telling someone you love them. There are things wrong with your world, but an excess of love is not one.
"The Humans" starts as a guide into the humankind written from the point of view of the super-intelligent alien. The alien is not familiar with Earth except knowing about its existence and sharing a limited set of prejudices about its inhabitants; this allows us to explore ourselves anew through its eyes. The author is succeeding a lot in depicting the alien's first experiences among us, filling them with a lot of cynical jokes and comments.
I have come to a planet where the most intelligent life-form still has to drive its own cars...
The alien arrives with a pretty explicit goal: to save the humankind and the universe (from the humanity) by slowing down its progress. The issue is that Andrew Martin, Mathematics Professor of Cambridge University, discovered a solution to the Riemann hypothesis. The discovery means an immerse scientific leap for humans: instant space travel, immortality, and anything else we can, and can not, imagine. And, according to the aliens who sent our hero to Earth, humans, destructive by nature, are not ready for this technological leap.
What I like about this book: an original alien perspective on humanity, the quite well thought-out beginning of the book, jokes in the first 2/3 half of the book, a few nice thoughts, emphasis on the value of human life, human relationships, kindness, honesty, love, care.
What I don't like about this book: that the author is bending established rules in the last third of the book, a blunt "deus ex machina" moment closer to the end of the book, and that author mentions a conflict between technological progress and humanity, intelligence and emotional ability, sensitivity.
Overall, the book is a good entertaining read, and I recommend it.