If there's ever a thing that's likely to get video game collectors whipped into a frenzy, it's special 'competition' or giveaway items which are only available in very limited numbers.
When you combine that scarcity with games that, in their Japanese form, are already on the rare side, then you get the dream combo for hardcore horders – and that's exactly what happened with Vampire Killer on the Mega Drive (known as Castlevania: Bloodlines and Castlevania: The New Generation in the West).
Back in the '90s, the Japanese magazine Mega Drive FAN ran a competition where it gave away a copy of Vampire Killer, housed in a gold cartridge.
As noted on social media by @jironosuke99, this competition has almost passed into the realm of urban legend, hence the timely reminder that this was an actual thing that happened.
If you need more proof, a post back in 2008 on the Assembler forums proves that the gold cart is, in fact, real:
"What caught my eye was a Vampire Killer Gold Cartridge, apart from it being gold, had a letter and a normal box it didn't seem much different. I tried to take a picture but got jumped on by the staff before I could even open my PDA... Oh they had NOT FOR SALE signs next to them too..."
Back on social media in 2025, @jironosuke99 recalls being told at the time of release by store staff that "the winner's name appears on the screen at startup."
Silver and bronze editions are also believed to exist, but only a gold cartridge has been spotted in the wild.
If you ever happen to see one of these carts on your travels, expect to pay a significant amount of cash to own them.