I had the good fortune to have read it completely for my own enjoyment and not for any type of reading assignment. I feel just the slightest bit bad for the person who read the book before I did. That poor unfortunate had the misfortune of having that book assigned to them for a class of some sort. I thank them for the margin notes -- they did come in a bit handy but I was still pretty lost. I had no idea what Arga Warga, the Punch Show or what Eusa was. A lot of it I began to pick up and others I was able to figure out from the context. Still it was a pretty difficult read. (Side note here... I am currently pursuing a Master of Science degree with a reading specialty. I want to help kids read blah blah blah... anyhow this book gave me the closest analogue to a student who can read a bit but not fluently. If any adults want to remind themselves of that feeling read Riddley.)
I caved about 3/4 of the way through the book and googled arga warga. I found out it meant 'a bad thing' (duh) and kept reading the annotated version. I very much regretted it. I ruined the ending for myself. Many of the questions I had were answered in that last quarter of the book. SO pissed at myself for ruining the book.
This book is apocalyptic a bit. Sort of like A Canticle for Leibowitz by Walter M. Miller and Vault of the Ages by Poul Anderson are apocalyptic. Sure the world has been mostly destroyed by a nuclear holocaust but it happened in the distant past. When I read a book about the end of the world I'd like for the event to unfold in the present tense and follow the characters as they cope and survive or die. Riddley was a great book even if the world ending event happened so far in the past that the characters in the book had forgotten about what had even happened. I'm glad I read it.
If you attempt to read it I recommend not giving in to temptation and reading the book without help from the interwebs. Just my advice.