"The Cube" tells the story of a group of what essentially are prisoners trapped in an hi-tech deathtrap for no apparent reason, by no explainable jailer. And in that same explanation, the purpose behind the cube becomes apparent: It does serve a purpose, whether it is merely to entertain the psychopathic whims of a person/corporation with too much time and money or their hands, or an experiment designed to foster the breakdown of basic decency in humankind, and bring out the worst in people. Despite all the numerous and gruesome traps in each smaller cube, they prove to be the least of the threats within.
The story can be taken with a lot of meanings. Some literal, some double, and some are never explained at all. Some story aspects, like the Cube itself, just ARE. And instead of feeling like the story was underdeveloped, or shortchanged by the need of more explanation, you're left with a sense of curiosity as to what really happened to bring all of these characters and factors together. Just when the viewer thinks it understands something, the story, like the cube itself, changes and becomes deeper.
All in all, "The Cube" was a fascinating film.
And it's good to see a film like that again.