I liked this movie far more the last few times I saw it than I did upon rewatching it. I enjoy many of the characters (or at least enough of them to make up for the ones I didn't enjoy), and portions of the story are perfectly fine, but this film lacks the charm of it's predecessor.
It possesses fewer trapped rooms than does the original, and while the bright white rooms bring a futuristic tone to the film, it doesn't do much for a suspenseful vibe. As with the first Cube, though, the strong point is not the surroundings or the story (and certainly not the conclusion, or lack thereof), it's the characters.
I'll say that I much preferred the antagonist from the first film, but the characters of Jerry (a kind, thoughtful if not overly cheery, man) and Mrs. Paley (an older woman with dementia/Alzheimer's) are both great. Jerry was the character who lacked the survival skills likely needed, but is an all-around good guy, whereas Paley's character brought some pretty humorous moments to the film. This is not to say the other characters aren't good, but some of them (the blind girl especially) became quite annoying as the movie pressed on.
The ending, while many disliked it, was one I felt was mostly acceptable. I do wish they delved more into the workings of the Hypercube, but the prequel gives us a small dose of that later on. Just a small note, I wasn't a big fan of the alternate reality/dimensions portrayed in this film - different versions of the same character getting killed multiple times, to me, really dampens the emotional response to the death - but it was certainly an interesting route to take. Not a great movie, and nowhere near as good as the first Cube, but this was passable. 6.5/10 (rounded down to 6/10 to fit site's format).