According to Yasushi Yamaguchi, Miyake was part of the team that, after Sonic 2, created a reference document defining Sonic's appearance for outside contractors. This team included Yamaguchi, Miyake, Naoto Ohshima and Satoshi Okano. 3 of these 4 people took part in redesigning Sonic in 1997 during an internal contest, and Yuji Uekawa's design was finally chosen.
(Sources: 1, 2, 3
Games
Other video game related works
Gallery
Advanced World War: Sennen Teikoku no Koubou / アドバンスド ワールド ウォー 千年帝国の興亡 (Saturn - 1997)
Package and manual (Source: in-game credits)
J.League Pro Soccer Club o Tsukurou! 2 / Jリーグプロサッカークラブをつくろう!2 (Saturn - 1997)
Publicity (Source: in-game credits)
Chaotix / カオティクス, AKA Knuckles' Chaotix (32X - 1995)
Chief Graphic Designer, Attraction Designer, Enemy Designer, Boss Designer, Original Character Concept (Source: in-game credits)
Character Design: Espio (Source: interview with Naoto Ohshima published in Untold History of Japanese Game Developers vol.3, p303)
Derby Tsuku 2 / ダビつく2 (Dreamcast - 2001)
Designer (Source: in-game credits)
Killer 7 / キラー7 (GameCube - 2005)
Character Design (Source: in-game credits)
Metal Gear Ac!d (PSP - 2004)
Card & 2D Design (Source: in-game credits)
Metal Gear Ac!d² (PSP - 2005
Card & 2D Design (Source: in-game credits)
NEO: The World Ends with You (PS4, Windows, Switch - 2021)
Cutscene Artist (Source: in-game credits)
NiGHTS into Dreams / ナイツ― (Saturn - 1996)
World Artist (Source: in-game credits + mentioned by Naoto Ohshima on Twitter)
Art director (Source: interview with Naoto Ohshima published in Untold History of Japanese Game Developers vol.3
Pen Pen TriIcelon / ペンペントライアイスロン (Dreamcast - 1999)
Character design (Source: in-game credits)
Psycho Break 2 / サイコブレイク2, AKA The Evil Within 2 (Windows, PS4, Xbox One - 2017)
Additional Creature Design (Source: in-game credits)
Riglordsaga 2 / リグロードサーガ２ (Saturn - 1996)
Advisory Staff (Source: in-game credits)
Ristar the Shooting Star / リスター・ザ・シューティングスター (Mega Drive - 1995)
Chief Designer (Source: in-game credits)
Sonic 3D Blast / ソニック3Dブラスト (Windows - 1997)
Enhancement Design (Source: in-game credits)
Sonic the Hedgehog CD / ソニック・ザ・ヘッジホッグ CD (Mega-CD - 1993)
Landscape Designer, Visual Design (Source: in-game credits)
Soul Sacrifice / ソウル・サクリファイス (PS Vita - 2013)
Concept Art: characters and backgrounds (Source: in-game credits + mentioned in an article published by Dengeki Online)
Described as one of the two main artists in several news about the book "Soul Sacrifice: The Art of Magic
Street Fighter IV / ストリートファイター IV (Xbox 360, Windows - 2009)
2D Movie (Animation Character Designer) (Source: in-game credits)
Zen Nihon Pro Wres Featuring Virtua / 全日本プロレス Featuring Virtua (Saturn - 1997)
CS R&D Publicity Team (Source: in-game credits)
Dreamcast Magazine - November 27, 1998 (magazine)
Cover art (Source: credited in the magazine)
NiGHTS: Tsubasa ga Nakute mo Sora wa Toberu / ナイツ―翼がなくても空は飛べる (picture book - 1996)
Illustrations (Source: credited in the book)
SegaSonic the Hedgehog Puzzle
Illustration (Source: mentioned by Naoto Ohshima on Twitter)
Sonic the Hedgehog redesign contest (1997)
Rejected design (Source: published in Harmony #154 (November-December 1997) and identified by his former colleague Satoshi Okano)
Soul Sacrifice Demo Issyo / ソウル・サクリファイス × どこでもいっしょ (clothing - 2014)
Illustration (Source: mentioned on the online shop Ebten)
Space Fishermen / スペースフィッシャーメン (PS2 - 2002)
Character design (Source: )
NiGHTS into Dreams
Pen Pen TriIcelon
Dreamcast Magazine - November 27, 1998
NiGHTS: Tsubasa ga Nakute mo Sora wa Toberu
Sonic the Hedgehog rejected design
SegaSonic the Hedgehog Puzzle
Soul Sacrifice Demo Issyo