Note: Things got busy this week, and I did not get terribly far with this project beyond a few doodles and workshopping encounter lists and creature abilities. I confess to a bit of writer's block, but I need to give myself a break, because every single "room" can't be an entire adventure unto itself. In keeping with this truth, I will ad some more "open road" areas.
1-6: The Quicksilver Lake
As the party descends into this area, the glass ground takes on a sodden feel, implying the presence of liquid. But the center of this area, a low point for this region of the map, is filled not with water but quicksilver. Or something like it. Over the ages, weird magical energies rendered from shards have coalesced into a thick, inert liquid, like mercury but without the, you know, brain damage and death and stuff.
The good news is that this liquid is very dense, so it is quite easy to float or swim across it. The bad news is that it is occupied by oozes, who have no problem disguising themselves against the silvery backdrop. Among these one will find crystal oozes, oblexes, gray ooze, metallic ooze and slithering trackers. These creatures typically lurk near the shore, waiting for the approach of a living creature such as an amalgam, striking out and dragging them into the lake where they have the advantage. And if a large meal attempts to wade in or cross, well! So much the better.
Even creatures made entirely of glass will float, so it's feasible that even a large amalgam would chase a tasty morsel out onto the lake. Note that all lake movement is difficult terrain, unless you somehow managed to rig up an oared vehicle of some kind.
Area 1-6 borders on 1-5, 1-7, and 1-13.