Koyasu has done the following roles in games.
Bulk Slash [Sega Saturn] Cless
Dai 4 Ji Super Robot Taisen S [Playstation] Shuu Shirakawa
Dancing Blade -Katte ni Momotenshi- [Playstation] Hachiku
Doki Doki On Air 2 [Windows, Mac, Playstation] guest
Dragon Force II [Sega Saturn] Shefard
Ellie no Atelier [Playstation] Crisis
Evangelion Koutetsu no Girlfriend [Playstation, Sega Saturn] Shigeru
EVE -burst error- [Sega Saturn] Amagi Kojirou
EVE The Lost One [Sega Saturn] Amagi Kojirou
EVE ZERO -ark of the matter- [WIN] Amagi Kojirou
EVE ZERO [Playstation] Amagi Kojirou
Farland Story [PC FX] ?
First Kiss Story [PC FX] Kousaka Hiroshi
Fushigi no Kuni no Angelique [Win95, Playstation, Sega Saturn] Olivier
Guilty Gear XX: The Midnight Carnival [Arcade] Eddie
Kindaichi Shounen no Jikenbo [Sega Saturn] Akechi
King of Fighters '97 [arcade] Shingo Yabuki
Magical Drop 3 [NeoGeo] ?
Meguri Aisite [Playstation] Kamijou Shunsuke
Misa no Mahou Monogatari [Playstation] Chikushino Hitaki
Quo Vadis 2 [Sega Saturn] Deon
Rururi Ra Rura [PC FX] Scott
Sakura Taisen [Sega Saturn] Kayama Yuuichi
Scandal [Playstation] Kagami Tatsuya
Shoujo Kakumei Utena [Sega Saturn] Kiryuu Touga
Wizard's Harmony 2 [Playstation, Sega Saturn] Arst
Yuukyuu Gensoukyoku [Playstation, Sega Saturn] Alf Coleson
Koyasu has done the following roles in CD/ RadioDrama
Battle Girl Ai [CD] Ichijou
Cherry Princess [CD] Churchill
Da Garn Mysterious Tour [CD] Seven Changer
Dennou Sentai Voogie's Angel [CD] Dr. Crimt
Houshin Engi [CD] Chuuou
Izanogi [CD] Shiva
King of Fighters 97 Drama CD [CD] Yabuki Shingo
King of Fighters 97 Gekitotsuhen [radio] Yabuki Shingo
King of Fighters 97 Shukumeihen [radio] Yabuki Shingo
Macross Generation [CD] Gana
Mahou no Maabou [CD] Maabou
Mahou no Maabou [CD] narration
Neon Genesis Evangelion [CD] Shigeru
Psychic Force [CD, radio] Burn Griffith
Puyo Puyo [CT] Mami
Sei naru Shoujo no Uta [CD] Kasumi Kaoru
Shoujo Kakumei Utena Engage-Toi Mes Cont Kiryuu Touga
SM Girls Saber Marionette J [CD] Hanagata
Sokkou Seitokai [CD] Kuroda Takehito
Solid Love [CD] ?
Susume! Super Angels! [CD] Dr. Crimt
Susume! Super Angels! [CD] Kurimoto
Tenchi Muyou Daiichi Otaku ha Dare? [CD] Pucchi
Weiss Kreuz [CD] Aya
Yuukyuu Gensoukyoku THE BEST -Selected by Characters- [CD] Alf Coleson