Don't get too excited for hilarious translations. If there was one thing Good Life was good at, it was translating their games. They had by far the best English translations of any Bootleg GBC company (that I have seen).

Off the top of my head IDs with the formats "JPK-NNN" and "PT-NNN" have the most in the way of cool undumped stuff (Good Life games). Carts with IDs "UANNNNN" and "CYNNNNN" have Makon games, so they may hold an undumped Makon game. UK-H3201 has an undumped title hack of Primal Rage. I also have a couple carts with an undumped sprite hack of a Sanrio-themed puzzle game. The hack is called "Kureyon Shin-Chan 6". Unfortunately my carts with KSC 6 do not have ID numbers.

To stay on topic, I'll leave some links to Good Life multis being sold on Ruten

https://goods.ruten.com.tw/item/show?21922547686327
https://goods.ruten.com.tw/item/show?21923636046136

*Note: For the ID numbers, replace the Ns with numbers.
*Note: Most multicart menus for Gameboy are undumped, but I do not think that is what you are interested in.

Question: do modern console games really count as bootlegs? You said it's for Switch... If that's the case, then maybe we should include the chinese Windows launcher for Android made by moban...

Based on the Contents/Articles page for the Wiki, stuff that is released for things that don't have much in the way of licensing are excluded from the Wiki. So, I would say that it is not about how old a bootleg is, but rather how it is released. (Assuming that we use the same definition of bootleg on the forums as the one used on the Wiki)
By that logic, Cooking Mama Cookstar would have a much better case for being a bootleg than moban's Windows launcher. If we are going off of Wiki definitions then I don't think Cooking Mama Cookstar counts either though. We tend to only count games that were released without permission from the console manufacturer to launch. Cookstar did not have licensing issues with Nintendo, just the rights holders to the Cooking Mama series. I would say that it falls more in line with stuff like the earliest releases of the Revenge of the Shinobi. It uses copyrighted material without the permission of its owner, but it did get the ok from Nintendo

I found a copy of the New Game Color Advance version of Digimon Saphire (same misspelling as their version of Pocket Monster Saphire) on eBay. The game does not seem to have a custom logo, but sadly the ROM does not work in any of my emulators. You can however look at some of the game's graphics by using stuff like YYCHR. PM me if you'd like the non-working ROM, just try not to spread it around (not that there is a functional ROM available to confuse it with)

I just got some stuff in from an eBay auction. The Good Life card game, and a few other Gameboy games, with the misspelling "Geam Byo Color". It also came with a Chinese copy of the first Last Bible game. Oddly, it does not seem to work on my GBA, but works fine on my other systems. Also, despite what the box says, this game is monochrome. Like a lot of these old translations, it cuts out the ability to name your characters. I'll include an IPS patch for it.

Some of my favorite mysteries are: What is Gowin game GS-14, are the rumored Telefang hacks "Pokemon Sapphire" and "Digimon Data" real, did SKOB ever make that sequel to "Milky Way" that they mentioned during the ending of that game, and what games did New Game Color Advance release. Truth be told, I am very interested in learning the libraries of all sorts of bootleg Gameboy companies. Especially ones that sell English (or really any language that is not Chinese) games. I am also pretty curious on how those old Gowin games got distributed (the ones with square shaped boxes, and grey cartridges). There are also quite a few bootlegs I have seen that I was never able to buy or ID. I'll attach a couple pictures of some of those unidentified games.

https://www.ebay.com/itm/Ultra-Rare-Monster-Adventure-2-Korean-PC-Game-Windows-CD-Collector-Item-Digimon/124109637058?hash=item1ce582c5c2:g:-ssAAOSwuEheNSC4

I just saw this strange looking PC game on eBay and figured I'd mention it here. It is a Korean game, and appears to feature some Digimon knockoffs on the front of the box, and a little Pichu figurine in the case. I cannot comment on well it plays (it appears to be a platformer), but this thing has one of the nicest bootleg game boxes I have ever seen

I recently found a Taobao listing that had a ton of unidentified Li Cheng games (almost all of them with IDs between CBA001 to CBA174), with screenshots of what the games are. Some of the games they show off are pretty neat. One that made me especially intrigued was "Rockman DX8" which according to the Pirated Games Museum page is supposed to be Sintax's Zook Hero 3. It isn't. It is Zook Hero Z (the first one). The picture of Zook Z shows English text. They also appear to have a Pokemon game with edited sprites for all the Pokemon, and a few re-releases of Gowin games. The seller also has some listings for Li Cheng's Mega Drive games, but I do not really play Mega Drive much. I'll attach a pdf copy of the listing, since I know these sorts of things tend to go down over time.

Note: I used Microsoft print to pdf, which messed up the how the pdf looks. You can still see some of the games on it (a few were cut off).

Here is a link to the page. It redirects if you are not located in China, but you can halt the redirect by using incognito mode on Firefox, or quickly downloading the webpage as an html before the redirect.

https://item.taobao.com/item.htm?spm=a230r.1.14.106.1a331b15AfSBKV&id=563443710012&ns=1&abbucket=6#detail