During the height of the Famicom's success in its native Japan, a peripheral was released that allowed players to play disk-based games for the system, which not only provided more data storage than the carts at the time but also allowed players to save their progress. Many early Famicom games were only available for the Famicom Disk System, as this peripheral would be called. These included the original Japanese releases of The Legend of Zelda, Metroid and other historically significant NES games.
Eventually, the FDS became out-dated as the technology behind the carts matched and then surpassed what was possible with the Famicom disks. During that time, the Disk Writer system was set up to allow owners of the device to purchase cheaper copies of games by letting them rewrite a disk's software at special kiosks throughout Japan. The games listed below are games that were only available via this service for the Famicom Disk System; they didn't receive any official retail release for the FDS.
For collectors of Famicom games in particular, Disk Writer exclusive games are difficult to track down. This is mostly because they are only available on loose Famicom disks, and since gamers could overwrite their old games there's no guarantee that the game label on any given disk is correct. For games that cannot be found on any other system - such as Eggerland: Souzouhe no Tabidachi - it becomes even more problematic.
It should be pointed out that many of the games below are available elsewhere, however. Most are ports of classic arcade games, which received many home versions. Some are even available as NES carts. However, for their FDS release in particular, they could only be attained through the Disk Writer service.