For my first submission I present an official Nintendo Gameboy Color Game that never saw a US, Japan, or European release:
Bomberman Selection was released only in Korea.
Not to be confused with Bomberman Collection, this title adds in full color support (so it won't work on an Original Gameboy or GBP), but you lose Bomberman GB2.
The one pictured was brand new, but I opened it just for you guys.
The Box, manual, and game menu are in Korean.
Here's the funny thing about this game:
In the menu you get to choose from Bomber Boy and Bomberman GB. Whoever was in charge of the menu managed to swap the names, so Bomber Boy is called Bomberman in Korea and vice versa.
I couldn't believe that whoever was in charge of this game only had to do 1 thing, and still managed to screw it up.
"Hey Mr. Park, the rest of the team finished colorizing the game. All you need to to do is type in Bomber Boy and Bomberman's name in Korean for their respective games. That's it. Don't screw it up."
Just FYI, the box says the game was made 4/30/2003. Which is at the very far extreme end of the GBC life cycle.
It is one of 3 Korean GBC games that I know of; the other two being Pokemon Gold and Silver.