The only thing more alienating than being stuck in Kafka's head is being stuck in the head of one of his characters. But he's such a brilliant weirdo that we just keep on reading.
This story is mainly told through the perspective of Gregor Samsa, as if the narrator were planted with Gregor's human consciousness inside Gregor's insect body. We discover aspects of Gregor's body as he himself discovers them. If he itches, we don't know why until he looks to see what's making him itch. If he's hungry, we don't know what he likes to eat until he discovers his preference for rotten foods.
The narrator does break out of Gregor's perspective on occasion and weaves into the minds of other characters, most notably in the last few paragraphs of the story after Gregor bites the bullet.