It's on my to read list: "Anticipation: The Real Life Story of Star Wars: Episode I - The Phantom Meance" by Jonathan L. Bowen (book is print on demand) has a chapter about the critical reviews which can be read at books.google: (pg. 89 but gets TPM centric around 92)

http://books.google.com/books?id=W1oyiL-Je6MC&printsec=frontcover&dq=anticipation+phantom+menace&source=bl&ots=1em8F3eQlb&sig=j8Jvi2MonMH-3lSxEpk-xgPLd40&hl=en&ei=YD-_TZa-HOby0gG0hKDKBQ&sa=X&oi=book_result&ct=result&resnum=2&ved=0CB0Q6AEwAQ#v=onepage&q=reviews&f=false

(the book has come up multiple times in searches, so i'm giving it a favorable rating from the small portions i've perused so far, but haven't read the full book.)

From the conclusion of the chapter:

pg. 99 Quote: "Overall, critics enjoyed The Phantom Menace, giving it average to slightly positive reviews. Few critics gave the movie under a two star rating, but few gave it it more than three stars either."