Jeff Minter has been designing video games since the early days of the medium. And since the very beginning an air of anarchy and trippyness has been a constant in his creations. Since Tempest 2000 he has been refining what I’d like to call the psychedelic “space” shooter (look here for Space Giraffe).
But he has released a game/ “light synthesizer” that is actually called Psychedelia as early as 1984.
Check out the man’s work! You won’t be disappointed.