Mary-Kate & Ashley: Pocket Planner (Powerhead Games/Club Acclaim, 2000)
It's secretly a reskin of the Austin Powers pocket planners from quite a few lists ago. I think this is the original version of the game, because the question text makes much more sense with this flavor than it did as a spy parody. Either way, still an impressively unnecessary bit of software.
Mary-Kate & Ashley: Winners Circle (M4 Limited/Club Acclaim, 2001)
This is, mercifully, the last game in the series. It's a steelplechase sim with nothing worth mentioning about it except that there's a "choose your outfit" screen at the beginning that only allows you to change which shade of solid color pants you're wearing. Not sure that counts as character customization.
Mask of Zorro (Saffire/Sunsoft, 2000)
This is remarkably un-shitty for something Sunsoft was involved with, but I suppose they weren't the developer and it does still have almost uncontrollably loose platforming. The main difference between this and every other character platformer is that there's a fencing system for combat. That could've been a really neat mechanic, except that mashing the forward attack was good enough to beat every enemy I encountered without taking damage. Alas.
Matt Hoffman's Pro BMX (HotGen/Activision, 2001)
I said much earlier in this series that I played the Dave Mirra games on GBA, but I'm pretty sure it was actually this series. Who knew there were multiple pro BMX games? Regardless, I'm glad I didn't play on GBC, because the controls are terribly and it's often difficult to tell exactly what's happening with these limited graphics.
Matchbox Emergency Patrol (Lucky Chicken Games/THQ, 2001)
You drive emergency vehicles around and respond to emergencies, but everyone in this town seems to have evolved for a universe in which toddlers get to drive 20 ton trucks around. If you go down the sidewalk, people do ninja moves to get out of the way, and cars swerve perfectly to avoid you even if you jump the median. When you finally get to the fire, the truck shoots out water in beams like it's a shmup, which I'm pretty sure is how fire trucks actually work.
Die Maus (Bit Managers/Infogrames, 1999)
There sure were a lot of German exclusives on GBC. This is some kind of isometric puzzle game, but since I continue to not speak German, I couldn't read the instructions and I'm not sure what I was meant to do with the immovable blue elephant, immovable giant boulder, and pacing porcupine.
Die Maus: Verrueckte Olympiade (Neon Studios/Infogrames, 2001)
Now the orange mouse is competing against the blue elephant in minigames that have nothing to do with the Olympics. This one seemed to be about pressing buttons in order to form a tic tac toe, but it's not very fun because the elephant has the levels memorized and just lasers between the buttons, but you obviously have to look for them. I found the best strategy was just to take advantage of being slightly faster than the elephant to run ahead of it and press every button it went to just before it could.
Maya the Bee: Garden Adventures (Neon Software/Acclaim Entertainment, 2000)
A European exclusive based on a German kids book from 1912. This particular version of it sees Maya's friend get kidnapped by wasps within literally 10 seconds of the game starting, which means she has to pay a ransom of a bucket of honey. From there it's some kind of boring puzzle/adventure game.
Maya the Bee & Her Friends (Crawfish Interactive/Acclaim, 1999)
Before the puzzle adventure game above, Maya starred in one of the many "ladder-based puzzle platformers" (OC donut steal) games on GBC. There are a lot of hazards like spikes and spiders that really shouldn't be in a bee hive, and for some reason none of the bees can fly. Clearly this is actually a horror story about humans who've been mind controlled into believing they're bees by aliens, when in reality they're completing dangerous tasks on the alien's ship. I've cracked the code, I've figured out these shadow organizations.
McDonald's Monogatari: Honobono Tenchou Ikusei Game (TDK Core, 2001)
"McDonald's Story: Friendly Manager Training" is pretty much what it sounds like: your big goal in life is to be manager of your local McDonald's, and for some reason you do that by going up to your coworkers and offering to take their place playing boring minigames that represent food prep work. I'm sure no one is surprised that what's obviously just an advertisement masquerading as a game isn't very interesting, but I picked this screenshot because it shows off a really bizarre font choice. The second character in the bottom row is supposed to be ん, but they've made it look like a drunk 'w' for some reason. I can only assume McDonald's was doing that in Japan in the early 2000s.
Golf Ou: The King of Golf
John Romero's Daikatana
Kakurenbou Battle Monster Tactics
Keitai Denju Telefang
The Legend of Zelda: Link's Awakening DX
The Legend of Zelda: Oracle of Ages
The Legend of Zelda: Oracle of Seasons
LEGO Island 2: The Brickster's Revenge