I was looking through some old Nintendo Powers, Game Pros, SWATs, and EGMs and found a number of unreleased games that were given reviews or scheduled for release which are not in the database. All of these games seemed to be intended for American release, some have detailed discriptions, most have developer names, and some even have screens shots. Here is a list of the ones which I found. I recorded page numbers for each so I can find them easily should more information be desired or others want to check it out for themselves. If you know that these games were released as something else.

Ultrabots: Sanction Earth
Radio Flyer
Joe vs. the Wall
Popeye
Sylvester and Tweety
Juggernauts
Matrix Prime
Mutant Hockey League
Cyberslider
Tarzan
Future Zone
G2 or Generation 2
Baby's Day Out
NFL Team Heroes
Lost Mission
Stop that Roach
Joe and Mac Jr
Code of the Dragon
Knights of the Realm
Bionic Volleyball
Jaguar XJ220
Rocky Mountain Sports
Rally's World Wide Soccer
The Journey Home
Super Dodge Ball
River Raid
Time Killer
Operation Alien
Firehawk
Fido Dido

Also, I found some articles on a number of unreleased games which are in the database. Some of these articles are detailed and some even have screen shots. These could be used to expound on the descriptions in the database. There were detailed articles on a number of them including The Savage Empire, Undercover Cops, Socks the Cat, Super Loopz, Sound Fantasy, and Fire Team Rogue.