Hahaha, I thought it would be wicked to be able to jump from one window by the waterfall to the other, but there's an invisible wall! This map feels kinda labyrinthine in the underground sections, they might be a bit too extensive and some of the walkways feel a little too tight for comfort, then again that might just be the risk you take going down there.
Some of the geometry is quite blocky and irregular, it reminds me of those old HL1 maps. Making the ramps/steps more in line with the style of in-game levels would help sell the map, make it feel like an actual place and not brushes placed in an editor. You've made huge leaps and bounds since the first screenshots. You've got a unique design with the underground section, kind of reminds of of koth_king in a way.
My advice (whatever that's worth) would be to simplify/reduce the size of the underground area and smooth out the geometry/play spaces to make them feel more comfortable for the player. Good luck!