At least on the PC version there are 4 apartments with the names "Keenan", "Chancellor", "Jones" and "Carey" on the doors. These are the surnames of the members of the band Tool.
The character Abbott was not originally modeled after Xzibit. Snoop Dogg happened to be visiting Vivendi when the game was being shown and commented on the character's likeness to Xzibit. He was then asked to voice the role.
Originally the opening sequence where Riddick is first lead into the prison was not to have an appearance by Abbott. Instead Riddick was to have been lead in by a normal guard who was voiced by John Di Maggio. Later the developers realized that the sequence would be all the more powerful if Abbott was the one to bring Riddick in.
Riddick's eye shine vision was originally meant to be much like the distorted effect in Pitch Black (2000). Due to complaints from play testers regarding headache and dizziness after playing several minutes, the effect was changed to resemble more closely the effect used in The Chronicles of Riddick (2004) which is similar to normal vision but with increased lighting and purple tint.
In Riddick's second escape attempt, an additional level was planned with an elaborate vehicle chase sequence. Riddick would then stop at "Billy Bob's Way Station" to refuel before being captured by Johns again. The sequence was scrapped due to lack of time and resources.