Wings of Fury (Magnin and Associates/Red Orb Entertainment, 1999)
A side scrolling flight game set in WWII. This was originally an Apple II game in 1987 and was well received back then. I'm not sure why, though, because endlessly flying left and missing all the targets because they pop up with no warning at all isn't much fun. I gave up after I got past the first island and had nothing but water to look at for a solid 30 seconds.
Winnie the Pooh: Adventures in the 100 Acre Wood (Tose/NewKidCo, 2000)
A roll and move game starring Winnie the Pooh. It seems like there are 8 stages and that you can eventually unlock minigames outside of the board game, but I don't want to play enough to find out.
Wizardry: Proving Grounds of the Mad Overlord, Wizardry II: Llygamyn no Isan, and Wizardry III: Diamond no Kishi (Game Studio/ASCII Entertainment, 2001)
All three of these are ports of early 1980s RPGs that were hugely influential for their time, but also wholly unremarkable by 2001. They all have identical setup menus and are only really differentiated by the color scheme of each dungeon. The GBC ports, which were all Japan exclusive, released on the same day and should've been on one cart. Even combined they'd be far from the largest game on the system.
Wizardry Empire and Wizardry Empire: Fukkatsu no Tsue (Starfish, 1999/2000)
More Wizardry, but this time with a town you can visit to do all those menu functions. It also has a coliseum for fights and a few other things that weren't in the older games. Dungeon crawling, however, is indistinguishable from those. These two games were original releases, not ports, and never made it out of Japan.
Woody Woodpecker (Planet Interactive/DreamCatcher Interactive, 2001)
A platformer in which you climb Woody Woodpecker's impossibly tall house and collect items for no reason, all while being attacked by other items for equally unclear reasons. You have an attack, but no one seems particularly bothered by it, and the music is on a loop that takes all of about three seconds to repeat.
Woody Woodpecker Racing (Konami, 2000)
This actually has everything it needs to be a solid racing game, except that they capped your speed at about a quarter of what it could be. It feels like you're playing the game in slow motion, and that's never something you want to be saying about a racing game. Also, this is supposedly the "city" track, but it clearly takes place in the woods.
Worms Armageddon (Infogrames, 2000)
Worms, but in a really low resolution, with repetitive music, and with an AI that takes absolutely forever to make moves for some reason. It might've been a good way to play on the go if you were really into the series 21 years ago, but that's about all I can say for it.
WWF Attitude (Crawfish Interactive/Acclaim Sports, 1999)
Probably the most basic wrestling game so far. There's almost nothing to see on screen, and Mankind here couldn't resist my incredible strategy of mashing punch without moving until I won.
WWF Betrayal (WayForward/THQ, 2001)
This isn't a wrestling game at all - it's a sidescrolling brawler. It seems like it's actually pretty decent, although you do have to deal with some very repetitive music. It'd probably go on the list if I enjoyed wrestling.
WWF WrestleMania 2000 (Natsume/THQ, 1999)
I'm pretty sure you can launch the space shuttle in fewer menu actions than it takes to get into a game here, but at least you're rewarded with something special when you finally get there. And by "something special", I mean a game with the very unique feature of an AI that tries to circle around behind you, gets lost, and then just sort of spins in place for 20 seconds while discovering the concept of 3D space. Eventually it figures out where you are, but the process repeats every time it tries to go behind you.
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
Metal Gear Solid
Millennium Winter Sports
Pokemon Crystal Version
Pokemon Card GB2 - GR Dan Sanjou!
Pokemon Puzzle Challenge
Pokemon Trading Card Game
Quest for Camelot
Return of the Ninja
Scooby Doo! Classic Creep Capers
SD Hiryuu no Ken EX
Shin Megami Tensei Devil Children: Aka no Shou
Space-Net: Cosmo Blue
Star Ocean: Blue Sphere
V-Rally: Edition '99
Wario Land II
Wario Land 3
Wendy: Every Witch Way