They rated GalCiv II's graphics as less than Darwinia's. I like Darwinia, thought it was a very good game but graphics wasn't...it's strongest point. They also rated Darwinia's music a full star ahead of GalCiv II's.
I played Darwinia too, and I don't understand that comparison either. The only thing cool about the Darwinia graphics, was that the game context allowed ultra-minimalist, abstract 3D creatures and terrain, and it still worked.
The graphics in GalCiv are a big step up from that. Maybe the reviewer played the game without ever zooming in on the galaxy map, and never fooled around with the ship designer? The high point of graphics in this game (IMO) is what you can do with custom ship designs.