I bought this for my 9-year old sister after we missed it in the cinema. I was hesitant because prequels can be disastrous, however this was a definite success. The plot is completely different to Monsters Inc. as you would imagine, but still works to incorporate some of the classic characters from the original film. We all thoroughly enjoyed it and would watch it again happily. Thus I would recommend to purchase it!
I know I am a bit old for Monsters films but we have all the others so thought I would buy this to go with the rest. As I have two grandchildren who will be watching them I wanted to complete the set. We watched it and I do not think it was as good as the others, there did not seem to be as much 'laugh out loud' to it. The grandchildren have not watched it yet so when they have I may need to updated this review.