We are talking about PROFESSIONAL not WELL DONE.

This means it is work that has to be sold. And therefore
has be be made with economical balance in mind.
Not just how it looks in the end.

The question was not "what defines a good art".

Some small recent games of mine:
Griefer 4k http://damocles11.byethost9.com/griefer4k.html
Kobold 4k http://damocles11.byethost9.com/kobold.html
Cave 4k http://damocles11.byethost9.com/cave4k.html