Bradbury usually writes pretty clearly. He's fond of using a noun, plus a verb, plus a little something extra just for fun. For instance: "The lions came running at them" (32).
But to be fair, the guy can get a little confusing, especially when he's making up words and describing new technology. For instance, "Now, as George and Lydia Hadley stood in the center of the room, the walls began to purr and recede into crystalline distance, it seemed, and presently an African veldt appeared, in three dimensions, on all sides, in color reproduced to the final pebble and bit of straw" (13).
That's pretty long, so it's fine to slow down and read these moments carefully, taking in all the little details, including the pebble. In fact, we can assume that's just what Bradbury wants us to do—read carefully. There are little clues he drops here which jump out when we slow down. The walls "purr"? Well, maybe that's just the sound of the tech in the walls, like a car engine. But maybe "purr" subtly prepares us for the lions to appear.
Also, there's a little difficulty with the POV (which we'll talk about in… oh, let's say our "Narrator Point of View" section). And also a little good ol' fashioned ambiguity in the ending (so go check out "What's Up With the Ending?").