The metal wand — the bit that heats up — is about 200mm long, and is somewhat flexible. It works OK, though it doesn't really get quite hot enough to cut easily through the insulation foam I use. I haven't tried it out on expanded polystyrene foam, which it's probably intended for — that stuff is even more temperature-sensitive.
It's not a precision tool though. I wouldn't want to try using it to cut up foam into regular geometric shapes, but for semi-random hack-and-slash work it's fine.
The boulders are pieces of pine bark that I nicked from a local playground some years ago. The bark is quite a dark brown in its natural state; I've just given them a couple of layers of dry-brushing to finish them off. I like using it for rocks; the texture is reasonably convincing, and it's much lighter than actual rocks.
A couple of days later...
I've re-done the water in the boggy patch, and it's a considerable improvement over my first attempt. This time, in addition to the 5-minute epoxy, I used a tiny drop of sepia ink to colour the "water" and a lot less acetone that before. Being more viscous than the first lot, I had to tease each blob out around its perimeter to blend it into the surrounding groundwork. It does create something more of a meniscus than with the very liquid first mix, but it's more controllable overall and creates deeper pools, which gives me some nice tonal variations.