Warren CHANG worked for Atari from 1982 to 1983 then became freelance and created illustrations for Atari and Sega (source: Art of Atari)
Games
Gallery Part 1
Gallery Part 2
Choplifter (Atari 5200 - 1984)
Cover art (Source: Art of Atari)
Combat Two (Atari 2600 - unreleased)
Manual illustration (Source: Art of Atari)
Math Grand Prix (Atari 2600 - 1982)
Cover art, manual illustration (Source: Art of Atari)
Moon Patrol (Atari 5200 - 1983)
Cover art (Source: Art of Atari)
Raiders of the Lost Ark (Atari 2600 - 1982)
Manual illustrations (Source: Art of Atari)
Realsports Baseball (Atari 2600, Atari 5200 - 1982)
Manual illustrations (Source: Art of Atari)
RealSports Tennis (Atari 5200 - 1983)
Production art (Source: Art of Atari)
Space Dungeon (Atari 5200 - 1983)
Concept art (Source: Art of Atari)
Strider, AKA Strider Hiryu / ストライダー飛竜 (Mega Drive - 1990, Master System - 1991)
Cover art for the European and US versions (Source: confirmed by Atari Historian Tim Lapetino on Facebook)
SwordQuest Airworld (Atari 2600 - unreleased)
Cover art (Source: Art of Atari)
SwordQuest Earthworld (Atari 2600 - 1982)
Cover art (Source: Art of Atari)
SwordQuest Fireworld (Atari 2600 - 1983)
Cover art (Source: Art of Atari)
SwordQuest Waterworld (Atari 2600 - 1983)
Cover art, concept art (Source: Art of Atari)
The Dukes of Hazzard (Atari 2600 - unreleased)
Cover concepts (Source: mentioned on the artist's website)
Track & Field (Atari 2600 - 1984)
Cover art (Source: Art of Atari)