I've been an artist all my life and I realized recently that people don't play games for the graphics. There may be a tendency to promote higher-res graphics, higher fps, and that sort of thing, but that is a byproduct of technological advances and the desire for more efficient systems.
You'll find that you can make really great games with very simple graphics, and people will appreciate them just the same. Graphics do help, so don't get me wrong- they are important and necessary for providing a surface to things- allowing people to relate themselves to what is happening.
I think it's more about how you utilize the graphics that matters to people. It doesn't take much for someone to identify what the graphics are representing, so it becomes more an issue of what happens beyond that process. How do the graphics change and interact with each other- how do they balance the circumstances and guide/pull the viewer into the world, etc. There should be a life to it that enhances the game experience.