John Madden Football - Old Games Download
Ubisoft's unreleased port of John Madden Football for the Game Boy has found its way online, The GoNintendo Archives
What video games have included features that were nothing more than placeholders for future game features that never happened? - Quora
A complete list of Beta & Cancelled Video Games
Madden Football 64 - Wikipedia
List of Nintendo Entertainment System games - Wikipedia
John Madden Football - Old Games Download
History of video games/Print version/Fifth Generation of Video Game Consoles - Wikibooks, open books for an open world
Let's Play John Madden Football [C64]
John Madden Football - Commodore 64 Game - Download Disk/Tape - Lemon64
John Madden Football - Commodore 64 Game - Download Disk/Tape - Lemon64
What games released pre-2005 are still worth revisiting? - Quora