I didn't like the sequels because I like the idea of not knowing the purpose of the cube, or if someone is watching them. It's fun to use our own imagination.
Some cool facts:
* Shot on a single 14'x14' set, made to look like many different cubes through the use of different-colored panels.
* All of the characters are named after prisons: Quentin (San Quentin, California), Holloway (England), Kazan (Russia), Rennes (France), Alderson (Alderson, West Virginia), Leaven and Worth (Leavenworth, Kansas).
* Not only are the characters named after prisons but they reflect the prisons themselves. Example: Kazan (the mentally challenged character), in Russia is a disorganized prison. Rennes (the "mentor") was a jail that pioneered many of today's prison policies. Quentin (the detective) is known for its brutality. Holloway is a women's prison, and Alderson is a prison where isolation is a common punishment. Leavenworth runs to a rigid set of rules (Leaven's mathematics), and the new prison is corporately owned and built (Worth, hired as an architect).
* To show their support for the Toronto film industry, the special effects company C.O.R.E. did the digital effects for free.
* Director Vincenzo Natali directed a follow-up short film in which we see what is outside the cube. Natali has made a solemn vow never to reveal what was outside the cube, and destroyed the video years ago.
* One of the earlier drafts of the script had the characters finding bizarre alien food. The idea was subsequently lost after it gave too clear a definition as to who was responsible for the cube.
* Leaven's broken glasses were cut in the same pattern as the panels on the walls of the cube. The idea was to show that everything in the environment was completely controlled.
* The handles on all the hatches are industrial die holders used for cutting threads on rods and available in any hardware shop.