hmmm, 1,000 words. I guess I'll save my 10,000 word analysis and review for my web site.
A few basic comments though - I don't think this movie is self-explanatory, at the level of mathematical theory. Which means, if you don't sometimes find yourself lying awake at night teasing your brain with multi-dimensional geometries, you probably simply won't enjoy it.
This is not about being smart or dumb - it's about your interests and pre-existing inclinations. I can think of subjects for films that would leave me wondering what the point is - ones where I don't have enough background or interest in the topic.
As a "sequel" this is dangerous. Whereas CUBE 1 was a nice mechanical device presented in a thriller, CUBE^2 is a deviously complex theoretical construct presented as science fiction.
I saw a copy of the used dvd for sale at my local video rent-all, and decided to rent the tape first in case, as most sequels do, this one was awful. Watched it twice that night. Bought the dvd. Have watched it about six times in a week... very unusual for me...
The film is chock full of presaging and detail. It is flawed, of course. I can think of twelve hours of scenes I would have like to have seen in it, and I bet the creators had to delete ten times that many ideas. It heavily rewards repeated viewing, but, even more so, stimulates curiosity, creativity and confusion for many more hours than it takes to watch it.
So my recommendation? If you read Flatland more than twice, if you occasionally dig out Einsteins little book just for beach reading, you'll probably enjoy the mental gymnastics of this film. If not, you'll probably think it is stupid.