The concept is not limited to KS and Nifflas' other games. It's quite possible to make neat Environmental levels in Spore's level editor too, for example. But whether they're common enough, I'm not sure.
The problem could be that to make environmental levels engaging takes more effort than most other types of genre, perhaps because of the lack of action. Good environmentals convey certain moods with well-chosen sounds and graphics, which I'd imagine requires some artistic talent.