Sankindo

Sankindo (三金堂) was allegedly an associated company of Face – perhaps it was a development subsidiary? The name stops appearing sometime in 1992 — maybe it was merged into Face? (In fact, 1992's Quiz Gekiretsu Scramble refers to the "Face Development Staff." Also worth considering: Designer Kenji Ishizaki's resume refers to Face, not Sankindo.)

Research Methods: Actual mentions, shared staff

Arcade

• Quiz DNA no Hanran (Face)
• Quiz Gakuen Paradise (NMK)

Sound: Arc System Works

• Sand Scorpion (Face)

Sound Programming?: Arc System Works?

Famicom/NES

• Chiyonofuji no Ooichou (co-developed with Arc System Works?) (JP Publisher: Face)

Game Gear

• Ryuu Kyuu / Solitaire Poker (JP/US/EU Publisher: Sega)

PC Engine/TurboGrafx-16

• Cross Wiber: Cyber Combat Police (JP Publisher: Face)

Music Programming: Arc System Works

• Fushigi no Yumi no Alice (JP Publisher: Face)

Programming Assistance, Music Composition: Arc System Works

• Hany in the Sky (JP Publisher: Face)
• Mahjong Gakuen: Touma Soushirou Toujou / Mahjong Gakuen: Touma Soushirou Toujou Mild (JP Publisher: Face)

Some Programming, Sound: Arc System Works

• Metal Stoker (JP Publisher: Face)
• Ryuu Kyuu (JP Publisher: Face)
• Time Cruise II / Time Cruise (JP Publisher: Face; US Publisher: NEC)