pinning it down to a particular developer or graphics artist
Jim Sachs was one of the early masters. The Wikipedia article about him does not do him justice: https://en.wikipedia.org/wiki/James_D._Sachs
One amazing thing was that even after the Amiga became available, he continued simultaneously making great art on the C-64.
I met Jim at users groups and trade shows and had to the opportunity to hang out with him several times. Not only an incredible artist but extremely humble and just a very nice human.