I think the universal truth of this book is change. Change is seen throughout the story in mostly Vladek. During the flashbacks of World War II, Vladek is seen as a resourceful and respectful man. He is polite and uses his cleverness to get himself through sticky situations. However, in the modern-day parts of the story, Vladek is obnoxious and tense. He whines about his wife Mala constantly and acts very cheap, not wanting to waste any bit of food or supplies. His time in Auschwitz probably changed his mindset, scarring him mentally, which is why he now acts this way.
I was most interested in the novel's action and symbolism. Since the whole book was a graphic novel (a comic) it was easy for the author to show action without using a lot of description in their writing. Feelings, events, and symbolism were easy to interpret because of the illustrations. Symbolism also played a role in this book. One such example was the species of the characters. The characters were depicted as animals (mice, cats, pigs, ect) to show who was what nationality. These characters sometimes used "masks" to "disguise" themselves as other animals, to show that the characters were pretending to be another nationality.
One flaw that MAUS has was it's lack of deep meaning. Although it contained much background information and some symbolism, the events and actions didn't really give off a sense of deep thought. Actions were prominent in the novel, mainly because of it's graphical nature. Other than that, I could not see any other flaws MAUS had.
I think anyone above 8th grade (or who knows enough about the Holocaust to understand certain events) would certainly enjoy this novel. MAUS gives the Holocaust another meaning and another point of view - through the depiction from a survivor's son. I have never been deeply intrigued by Holocaust memoirs/novels/re-tellings, but this one surprised me with it's fascinating point of view and depiction of the characters as animals. I was better able to understand the horrors that went on during World War II, none like other novels (such as Night) have. I was so satisfied and interested that I picked up the second book as soon as I finished the first!