Astroll Co., Ltd. (株式会社アストロール), headed by Junichi Mizutari (水足淳一), was originally established on April 28, 1977, as 有限会社ユニック (Unic? Unique?). It became Astroll in June 1997. 
The company profile linked above does not mention anything about Lenar Co., Ltd. (株式会社レナール). It apparently had its own website , so it likely was a separate company.
- Bird Week (JP Publisher: Toshiba EMI)
- Image Fight (JP/US Publisher: Irem)
- Major League (JP Publisher: Irem)
- Mashou / Deadly Towers (JP Publisher: Irem; US Publisher: Brøderbund)
- Napoleon Senki (JP Publisher: Irem)
- Tetris 2 + BomBliss (JP Publisher: BPS)
- Junichi Mizutari is credited with bomb sound digitization.  Did he do this on behalf of Lenar?
- Zombie Hunter (background graphics, sound, voice synthesis) (JP Publisher: Hi-Score)
- Battle of Kingdom (JP Publisher: Meldac)
- F1 Boy (JP Publisher: ASK Kodansha)
- Knight Quest (US/JP Publisher: Taito)
- Tenjin Kaisen / Mercenary Force (JP/US Publisher: Meldac; EU Publisher: Nintendo)
- Klax (sound?) (JP/US Publisher: Tengen)
- Mizutari is credited with audio.
- Monster Pro Wres (JP Publisher: ASK Kodansha)
- Off the Wall (sound effects?) (Tengen)
- Mizutari is credited with "Sound FX."
Super Famicom/Super NES
- GT Racing (JP Publisher: Imagineer)
- Gunman's Proof (JP Publisher: ASCII)
- Magna Braban: Henreki no Yuusha (JP Publisher: ASK Kodansha)
- Shushoku Game (JP Publisher: Imagineer)
- Sun Spo Fishing Keiryu Ou (JP Publisher: Imagineer)
- Touge Densetsu Saisoku Battle (JP Publisher: BPS)
- Akiyama Jin Kyouju Kanshuu: Zennou JinJin / MinDStorm / Master Jin Jin's IQ Challenge (co-developed with Altair) (JP Publisher: ASK; EU/AU Publisher: 505 Games; US Publisher: Valcon Games)
- Cocktail Harmony / Cocktail no Recipe (JP Publisher: Astroll/D3 Publisher)
- Itadaki Street: Gorgeous King (some graphics) (JP Publisher: Enix)
- Scenario, Game Design: Armor Project; Developer: Tomcat System; Some Graphics: Algo-Nicus, Goukaido; Sound: BeatManiac; Opening Movie: Shadow Entertainment
- Sound Novel Evolution 2: Kamaitachi no Yoru Tokubetsu-hen (JP Publisher: Chunsoft)
- American Arcade / Pinball (JP Publisher: Astroll; EU Publisher: Play It)
- EX Billiard / Real Pool / International Cue Club (JP Publisher: Takara; US Publisher: Infogrames; EU Publisher: Midas Interactive Entertainment)
- Hello Kitty no PikoPiko Daisakusen / Hello Kitty: Roller Rescue (JP Publisher: Hamster; EU/AU Publisher: Xplosiv) 
- Mahou Tsukai Kurohime (JP Publisher: Tomy)
- Shinjuku no Ookami (JP Publisher: Spike)
- Seikan (unreleased)
- Tokyo Majin Gakuen: Fuju Houroku (programming) (JP Publisher: Asmik Ace Entertainment)
- Planning, Scenario, Some Graphics?: Shout! Design Works; Programming: Feathered?; Some Graphics?: Mcreate, Site Design?