Flatland is, in many ways, delightful. Abbott exercises wit and imagination to depict what it would be like to live in one two, three, or no dimensions--and what it would be like for an inhabitant of one to visit another. I learned quite a bit.
But in addition to being a mathematical story with plenty of insight on geometry, it's also a rather pointed satire. Some of it is quite funny. The King and sole inhabitant of Pointland is unable to imagine anything in the cosmos except himself, and when the Sphere from Spaceland descends from outside Flatland to enlighten our hero to the existence and wonders of Spaceland, and the humble Square (finally acknowledging the existence of a third dimension) posits the existence of a fourth, fifth, sixth, and infinite additional dimensions, the Sphere immediately disapproves.
There is also much political and social commentary, surprisingly for such a short book on such an esoteric subject.
Flatland is only a very short and amusing read, full of geometry and irony, as well as being a classic of science fiction. I enjoyed it.