A very strong 4.5.
This is the book that 'Ready Player One' and all of that ilk want to be. It's strength is it does not shy away from 'a corporation did it' by setting up some 'evil overlord owner' as the antagonist. Corporations are indeed 'doing bad stuff' and its not necessarily steered by evil individuals.
A post climate change world. People are living in megacities built on the ruins of the old and as always there is an underclass. The underclass is controlled by the fact that water is 'owned' by the corporation and that to get it they must hustle. Whether that be in some gig economy nightmare or the hustle of online gaming. The modern day 'bread and circuses'. This is all very well realised with the parallels to the situation today plain and thought provoking.
At heart though, this is a book about people who have nothing choosing to care about an injustice they could just as easily walk away from. Paying dearly for that concern. Such as it ever was.
Definite recommend.