An eccentric robot saves the solar system with his 14 year old accomplice.
About 33 thousand words, or a 3 hour read.
Out of children’s fiction books about robots, I’d say it is 4 stars. As it would probably be entertaining for a child, it being a grand adventure to save the world.
For an adult reader though it is closer to 3 stars, mostly because it is rather shallow and unrealistic. Still it is readable.
Particularly if you have pubescent child who may much enjoy it, I’d recommend it.
Can get it for under $10 on bookfinder.