It's short, generally readable in a day. The transformation of the main character - Gregor Samsa - into a massive vermin (ungeheueres Ungeziefer) is hilarious and absurd. Initially he seems not to want to believe his transformation, does not notice its severity, and insists that he can keep working as a traveling salesman. The reaction of his family on the short and long term is what makes this book the social critique that I see in it. His family, moments after the discovery of his transformation, starts worrying about their livelihood, the loss of an income, the payment of the rent. There is no curiosity why it might have happened, no attempt or ambition to revert the process, no doctor is called, especially curious for the fact that the city hospital is across the street. In fact, the hospital is the only thing that Gregor gets to see from the window of his room.
Instead of self-pity or anger, Gregor is mostly ashamed. He puts a tarp over himself when his sister or mother comes in to feed him food scraps. He loves his family and feels disgusted by his appearance and inability to provide for them. Would it have been different if he had not been the exception? Would he have thrived in a society composed of beautiful insects instead of 'Ungeziefer'? He is still a social being and devastated that he is now the exception, having worked so hard to meet the norm.
The 'kleinbürgerliche' attitude of the family, the narrow-minded, self-centered and materialistic reaction to Gregor's predicament manifests itself with increasing severity towards the end of the story. When Gregor shows himself in the living room, his father throws an apple at him, wounding Gregor for months. Anger presides, the father chases Gregor through the living room as punishment for leaving his room (or prison), for attempting to be a human. At some point, his sister pleads that 'something should be done about Gregor', not out of love for her brother, but about a kind of utilitarianism towards her family.
Gregor grows weaker, he dies while expressing his love for his family, they go out for a lovely day to the park, feeling relieved and thinking about their future. To them, Gregor had already been dead.
'Kafkaesque' is generally seen as a word describing a societal power structure, like a legal or governmental body, that is complex, irrational, of which only limited knowledge can be obtained, and that wields uncomfortable power over its subjects. In the Trial (Der Prozeß), Kafka's longest work and my favorite book by him, the main character is indeed entangled in a legal trial over which he has no power. It's this lack of control and the subjection to power that can be seen as well in 'Die Verwandlung'. In the case of this short story however, this power comes from society and family. Arguably even scarier, since Gregor Samsa has full knowledge of their hate for him after his transformation. There is no obfuscation, no mystery - yet still a real Kafkaesque description of irrational power. It reflects the potential horror of social pressure, it is a warning against the 'tyranny of the majority' as described by JS Mill.
I definitely recommend reading it for its social critique and vivid storytelling. Additionally, I recommend to read 'der Prozeß', as both stories complement each other.