For mine the funniest part was when Narcogen made a joke, and Blackstar said it was not funny :).
As far as difficulty goes, Narcogen admitted ignoring a few progression points - the lava swim being the best example. I think for this series "jump right in" needs to be the approach more so :). I do recall finding the later part of the level confusing, though. Perhaps they should run with the showallpolygons plugin you (PS) were using? Except then there would be issues with knowing where they had been and not.
And one outstanding question: what did that secret L switch actually do?
As the series progresses you might also need to run past enemies in high up spots more, especially on The Gauntlet, which kind of speaks for itself. Not sure how far you have got by now. Polygonium Opus might come across as hard as well, but then *I think* it should be okayish until Theater of Pain, where you -have to- grenade jump onto a pillar to continue the level at one point. That was a nasty piece of design. Hopefully the spoiler guide is better worded by then :). Sorry for not catching up with ToD - PS, where are my next map pics? ;)