I'd imagine readers already know about it, but Ebert posted another article about his opinion of video games as art. His stance reminded me of a Calvin and Hobbes strip about the difference between high and low forms of art. I'll repeat it here, substituting "short film" for "painting", "video game" for "comic strip", and other words as appropriate.
A short film. Moving. Spiritually enriching. Sublime. "High" art!
The video game. Vapid. Juvenile. Commercial hack work. "Low" art.
A short film spoofing a video game. Sophisticated irony. Philosophically challenging. ..."High" art.
Suppose I make a video game that contains a short film spoofing a video game?
Sophomoric. Intellectually Sterile. ..."Low" art.