For the first time on the internet, here's a from-emulator video of Super Gun, one of the rarest games for the original NES! We just helped to extract the data for this, but we had to find a REALLY weird workaround (thread):
Super Gun was released around 1992 as a standalone, commercial cartridge by a company called NTDEC. It even came in multiple variations: the 60-pin Famicom version here is the only one I can find a picture of, but there was also a 72-pin NES release in some places. 
If you're familiar with the American library for the system you probably haven't heard of NTDEC, but maybe you HAVE heard of its short-lived American counterpart, Caltron? Its "unlicensed" 6-in-1 compilation is one of the hardest games in the set.
6-in-1 contained a mere 6 of NTDEC's full catalog, which was somewhere around 20 titles at that point...Super Gun among them. In fact, Super Gun was planned to be included in the sequel to Caltron 6-in-1: the unreleased "Caltron 9-in-1"!
Here's a sales brochure I scanned from that year's CES showing the 6-in-1 and 9-in-1 carts side by side (along with another game that never made it out in the U.S., a Street Fighter II-alike called Fighting Hero).
Anyway, back to Super Gun. The cartridge turns out to be one of NTDEC's rarest. The only copy we know of is owned by a Japanese collector who would have no part in distributing the ROM on the internet (though they WERE cool enough to let it get dumped and dissected privately).
So while we had the inner workings of the game and its PCB "mapper" well documented, we couldn't actually play the game. The owner was not interested in selling it, and literal years of an eBay alert were fruitless. What to do!
Besides the Japanese collector, it turns out we did have one other source of this game: the unreleased 9-in-1! It turns out exactly one prototype survived. And its previous owner...paid a lot of money to permanently encase it in a VGA slab before they backed up the ROM.
Oops.
I didn't know this until recently, but the game was sold privately to a friend of mine (and yours!), Sean Fontenot. And Sean very graciously agreed to let us dump the ROMs for posterity. He broke it open himself and delivered it to me at Portland Retro Gaming Expo last week.
Here's Sean at the show playing his very expensive game for the first time before I took it home to work on it.
Anyway, long story short, the game has been extracted and emulated, along with an extracted copy of Super Gun. More here:
Here are you takeaways from this lecture:
1. Game preservation is weird sometimes
2. Maybe be cool and nice to our collector friends before you call them hoarders, they're the ones who actually have this stuff!
3. DON'T SLAB UNDUMPED GAMES WTF IS WRONG WITH YOU
1. Game preservation is weird sometimes
2. Maybe be cool and nice to our collector friends before you call them hoarders, they're the ones who actually have this stuff!
3. DON'T SLAB UNDUMPED GAMES WTF IS WRONG WITH YOU
Someone (not me) with access to the original says that it's very likely the only change is the copyright text on the title screen.
FYI this is the official song of this thread, it's my thread and I said so
