What about his contributions to human civilization? ;)

He got a world record score on the Tempest arcade game [1], then developed an AI which beat his own record[2]. His biggest failure was, that after rebuilding TEMPEST from arcade machine ROMS, he added levels to the game but never made them public [3].

[1]. https://www.youtube.com/watch?v=EuSMCWu02hA

[2]. https://www.youtube.com/watch?v=TdbpoDjIvPk

[3]. https://www.youtube.com/watch?v=BjsVSEbXDOM