Hmmm...you both could be right. In fact, if the graphics had been enhanced they'd advertise this on the distribution site as it'd be a definite selling enticement.
Btw, did you notice where they have a page offering to sell other people's software? We could upload the Abandonia game there when it's finished
Edit:
Just noticed this on the page with larger screens which I think answers the question:
'California Gold Rush's graphics are not high-res by today's standards, but the colors are lively and animated objects bring the screen to life.'