Metroid

From GreenWedge

The Japanese version of Metroid ran on the Famicom Disk System, which used floppy disks, not cartridges. Saves were written to the disk. Since Metroid had lackluster sales in Japan, when the game came stateside, the budget wasn't high enough to include a battery in the cartridge, as had been done with Legend of Zelda. So, the programmers came up with a password system.

As a result, in order to keep your progress, you have to put in this looooong password every time you play. Fortunately, thanks to emulation, you can now play the original Metroid, and dispense with passwords altogether! (Actually, you could dispense with them anyway, since most emulators have a "freeze" feature, but since that would be cheating, I'm not going to consider that.)

Besides having a save system, Metroid on FDS also has much better music than the US version. One minor annoyance is the load times. Since the FDS was disk, not cartridge-based, there are load times, even in emulation. Also, you have to flip the disk over every time you load or save. In Mednafen, the key combo is F8 (eject disk), F6 (flip disk), and F8 (insert disk).

AlanMidas has an English translation here. (Note: To load IPS patches in Mednafen, the patch must have the same name as the ROM. If your ROM is named metroid.nes, then the patch must be named metroid.nes.ips)