Cube was a good little movie. Interesting concept, well developed tension (sometimes effectively stretched to near breaking point), modestly budgeted but well executed production design, a hinted-at milieu that was semi-plausible, and Nicole deBoer.
Hypercube wasn't. The dialogue was baaaad, there was minimal tension, the acting mostly over-the-top (Kari Matchett who played the main character Kate was the best of a bad bunch, but even she seemed bemused half the time) and the traps and technology too overtly SF for the sake of setting up some visual sequences. Some of the FX were interesting though and the production design continued to be minimalist and sleek.
I don't think there's going to be a Cube-cubed.
Cypher was a much better sequel to Cube. It had a similar sense of style, mystery and paranoia (not surprising it was directed by the same person) and could - effectively - be set in the same world.