What's missing is what our website does not accept: demos without extra content and unreleased prototypes, all of which account for the 20 or so extra "games" you may see on various lists. Every other disc ever released for that console in any region is documented, including unlicensed and all known homebrew games that were released on physical discs.
Without false modesty I want to pat myself on the back, since it was yours truly who contributed the majority of the entries.
I'd like to thank everyone who helped contributing and also approved my submissions. Of particular mention is the incredible work done by Jotaro Raido. Not only did he help me avert mistakes and achieve a high level of accuracy with his valuable advice during approvals - he almost single-handedly filled up our PCE CD database with a vast amount of Japanese credits.