Haha, I just browsed around Bottomless Pits a bit, pretty awesome :D Did you ever play Journey? You can't fall through the floor in that game, but there are ways to get "inside" the various levels by glitching through stuff, it was pretty fun. Youtube has some vids of it if you're bored.
As for graduated cylinder, I don't think it "goes on" in any particular way in general, the level orders are random and I played through the whole game a second time after recording to see if I missed any levels, and didn't run into any so I figurd I got 'em all.