Yes, it's still very impressive. At any point in time these images could have gone up on gamedev.net as screenshots of the day/week.
To those saying he should sell this game, I disagree. This is obviously a very interesting and personal project and commercializing it would take a lot of the joy out of the work. It's also something that is obviously in perpetual evolution. Once there's a release, that adds constraints compared to freeform development.
This genuinely makes me want to come up with some sort of long-term (life-long?) project. Like the Sistine Chapel... but not as good. :)