I know I'm bumping a relatively old thread 
I have most pippin @World games (I'm missing cool crafts, exotic sushi, and home improvement 1-2-3). Sadly they are all sealed so it's been hard deciding whether to open them or not as I'd like to make backups to so that they are never completely lost. I've been thinking when I get time I'd like to open them and make comprehensive scans of all the artwork, documentation, disc cover and also dump them... but I haven't had any time lately.
Off the list of titles commercially released in the united states (on Wikipedia) I think that some of the titles are speculated to have been released due to their appearance on the inside of the digipak cases but haven't actually been released. For example, I believe pegasus prime was released for the mac a full year after the last pippin game had been released. I have also never seen any evidence of Terror Trax getting a release. To a lesser extent play dough creations and Movieoke don't seem to have been released either. Some lists include gundam, I don't think that was released either. Of course, the only real evidence that any of these games exist is largely in the thread that was linked to in post #18 so it's possible there are others out there.
CineNoir
Compton's Interactive Encyclopedia
Cool Crafts
Exotic Sushi
Gus Goes to Cyberopolis
Gus Goes to the Kooky Carnival in search of Rant
Home Improvement 1-2-3
Movieoke
Mr. Potato Head Saves Veggie Valley
Navigator
Pegasus Prime
Power Rangers Zeo Vs. The Machine Empire
Playskool Puzzles
Play-Doh Creations
Racing Days
Super Marathon
Terror T.R.A.X.
TV Works
The same thing applies to many japanese releases. There is a pippin catalog disc but only about 75% of the games featured ever seem to have gotten a release. Not really a big deal imo because I'm not sure I even saw one unreleased game in there that would've been worth playing. There are some additional Japanese games that seem decent, but the number that are actually enjoyable is greatly reduced if you are not fluent in Japanese.
I am looking for obsolete games for a obsolete system which was also a market place failure, making it ten times harder to find any games for this system, however I want to play games on this system. I want to be able to use it and enjoy it, but I can't.
Now you two point me to a shop which is selling the games I have mentioned above brand new (or even second hand) for a reasonable price, and I will buy them... No, nothing? I thought not. I have looked and I have tried and asking for some help in locating these is my final option.
I should point out two issues with what you wrote though...
(1) Most of the @World games are not games and are not very enjoyable. The only ones I found myself liking were Power Rangers (this game is riddled with bugs and sloppy programming, but it's very creative and had some decent design... kind of a guilty pleasure) and super marathon. Racing Days is trash but it's a good technical example on the system.
(2) A "reasonable price" is relative to what you think it is. Pippin games sell for an absurd amount of money if you buy them on sites like ebay (maybe you can get lucky with a pawn shop or friend of a friend type find).