Snake's never been more well-hidden than on the Game Boy.

Among the franchise juggernauts of the video game industry, director Hideo Kojima's Cold War tactical espionage thriller Metal Gear is famous for its advanced stealth mechanics, over-the-top characters and convoluted plot spanning across decades of entries; a reputation that will likely prove to be justified with the upcoming release of Metal Gear Solid Delta.
Given this, if you were publisher Konami, how would you deal with an obscure entry taking place in an alternate continuity? Well, not all, apparently...
Leaving Outer Heaven
Originally released on the MSX2 in 1987 along with a heavily-altered port to the NES, the first Metal Gear quickly gained enough of a cult following to warrant the release of two immediate successors, namely the now-disowned, Kojima-less Snake's Revenge and the actual sequel Metal Gear Solid 2: Solid Snake, both in 1990.
The latter would go on to serve as the template for 1998's Metal Gear Solid, which catapulted the franchise into the third dimension and added mind-boggling plot twists, action sequences and philosophical undertones which paved the way for the franchise to become a worldwide sensation and for stealth games to really take off.
It's somewhat curious then that this PlayStation hit would serve as the starting-off point for the THIRD parallel direct continuation of the 1987 entry, when Konami of Europe asked for it to be ported to the Game Boy Color, finally resulting in 2000's Metal Gear: Ghost Babel.
Shadows of Shadow Moses
The developers at Konami Computer Entertainment Japan and Tose quickly realized that trying to accurately replicate the impressive action setpieces of the PlayStation game on the Game Boy Color would be futile and thus decided to come up with their own levels, characters and premise, set seven years after the very first Metal Gear.
Instead of the crushing of the fictional Outer Heaven Uprising (where South African mercinary stronghold Outer Heaven tried to use the first titular Metal Gear weapon to disrupt the balance of power) eventually leading to the Shadow Moses incident depicted in Metal Gear Solid, the alternate continuity in which Metal Gear: Ghost Babel takes place in shows it instead leading to the Galuade Incident.
While we don't want to spoil the story here, we can assure you that Ghost Babel does an exceptional job immersing you in its action (given the constraints of the hardware). The main campaign plays like a mixture of Metal Gear 2 and Metal Gear Solid, which would be good enough on its own, but the game also features various VR missions, multiplayer and hidden lore modes as well, making it absolutely worth a try!
Cover-Up of Galuade Incident

...If you can, that is. The closest thing we've ever gotten to a re-release of Metal Gear: Ghost Babel (confusingly sometimes just called Metal Gear Solid for Game Boy Color) is an adaptation of some in-game text as a radio drama, featuring Hideo Kojima, in 2006.
This implies that the long-time director of the franchise at least knew and appreciated the game, really making you wonder why it was never playable outside of the original Game Boy Color release. Perhaps they intended to not mess with the already-confusing Metal Gear story even further by acquainting players with a non-canonical entry? Or it could be due to the game being designed to rely on particularly edgy themes and characters in order to not be received as "another child-friendly Game Boy title".
After the dispute between Konami and Kojima caused company and creator to go their seperate ways in 2015, the franchise was in limbo for the longest time, but when the Metal Gear Solid: Master Collection was finally released in 2023, even the previously long-ignored Snake's Revenge was included, really showing just how desperately Konami (seemingly) wants you to forget about Ghost Babel.
Unpaid Mercenary's Work
The critical and fan reception certainly isn't to blame, seeing as the game often ranks among the top Game Boy Color games and is generally considered a really good standalone entry in the franchise.
Aside from some really-well hidden references in games like Metal Gear Solid 2 (but hey, at least the game's allowed to be referenced, unlike comparable games like Sonic Pocket Adventure) the memory has been kept alive mostly by fan discussion and fan mods, such as inserting Ghost Babel's setting of Galuade into Super Smash Bros. Crusade as a stage by modder Rukifelth in March 2022.
A fangame by IcedCris, which seeks to convert Metal Gear Solid and Metal Gear: Ghost Babel into a competitve online multiplayer adventure was announced to be in development in June 2023. Until more comes of that, we can only hope for Konami to come to their senses and re-release the game as part of a Metal Gear Solid: Master Collection Vol. 2 or on the Nintendo Classics service.