I found it hard to think of what exactly to say about this. Because I wasn't sure what to think, and this book was one of the first of its kind and I wouldn't feel right judging it a few centuries later, I didn't give it a star rating. That didn't stop me from writing several hundred words about it, though; sorry. 
 Frankly, I didn't like about 50% of the book. The first 70 pages is spent on an unrelated character - the captain of an arctic exploring ship who happens to meet Dr. Frankenstein. I am sorry I read those 70 pages, and I would recommend that anyone taking up the novel for the first time and wanting to enjoy it should start at Volume II. 
 Once the story actually starts, with Frankenstein telling his story to the captain, it gets interesting. Or it would, if Frankenstein didn't spend an incredible amount of time describing his surroundings to the captain/the reader. I really couldn't believe that the author thought it would be a good idea to take several pages at a time just describing lakes he rowed a boat on, mountains he climbed, etc. That was probably another 30 pages. 
 The monster is described as hideous, although it is never actually described. If I remember right, the monster is just quite large and has white eyes. Everyone the monster meets evidently thinks he's pretty hideous, but I just wish the author would have given us a little more to picture. 
 When the monster finally confronts Frankenstein and tells the story of his short life, the book was *really* great, and I couldn't stop reading. His development, his attempts at friendship with humans, his rejection, his revenge - all of it was fantastic. I could read a whole book of the monster telling of his life, and I wish there was such a book. 
 Frankenstein himself spends most of the novel unconscious because he's apparently a Victorian lady and is taken ill at anything that upsets him. I think the monster is the most interesting part of the book, while Frankenstein is just not a very good character. I wish the book had focused on the monster with only small parts for Frankenstein. 
 However, I'm saying all of this with the benefit of a couple hundred years of other books that have built on Frankenstein, but since it was either the first or one of the first "horror" novels, it's an impressive achievement for 18 year old Mary Shelley; I am impressed, but not entertained, and that's only because since 1818 many better books along the same themes have been written.