That I'm interested in and can actually play now that I got this Dell Dimension 4100 and iMac G4 working with Japanese text. Some might have localised releases but I'll cross that bridge when I get to it :o)

Not on IGDB:
Underworld
Samurai Mech
The Alius
SCOP
ios
Golly Ghosts Goal
Mayu
AlexWorld
Ankh 1-3
Nova City
Masters of Elements: Unmei no Shihaisha
Virtual Walk English 1-3
One Two Animal: Let's Animal Series
Murphy da yo Zen'in Shuugou!!
Warlocks (1998)
Penguin Piano
Vaachapaaku The Fisshu 2 Sodatete Pukupuku
Secret Safari
Curio City 1-11
Popee the Performer Carnival
Earthtia Saga
Funky Funny Aliens
Jya Jya
Macaroni Hourensou Interactive
Racing Days
Refixion
The Yakyuken 1-5
Angel Gate
Daina Airan
Dice Fantasy
Elder Blaze
Flappy 95
Henry Explorers
Kujira Monogatari
Link Devicer 2074
Miss - Interactive Hard Boiled
Pastel Pop
Wankuru
Zeitgeist
Dark Fiber
Paradise Rescue
Electronic Popple
Clone Ranger
Kumdol no Ken