Cube 2: Hypercube is a disappointment that fails to evolve from its predecessor’s unique premise. Instead of expanding on the original’s physical death traps, it explores time and space with concepts like multiple copies, time dilation, and time travel. The result is a confusing, tension-free mess that lacks coherent rules. In contrast, the prequel Cube 0 returned to the physical traps, which were more entertaining. This sequel’s attempt at innovation falls flat, making viewers wish for a simpler, more familiar follow-up.
Source: https://whatculture.com/film/10-horror-movie-sequels-that-took-risks-and-failed?page=6