Cacti

World progress:
Sea: I modifed the reflections so they're actually visible at low zoom levels, and added a sort of "specular" highlight from the Sun. I may have to tone it down a bit, though.
Sky: As before.
Land: I implemented a texture atlas shader in place of the splatting shader I had before. It uses a noise mask to generate irregular borders between terrain color patches. The overall effect is currently somewhat too "tiled" for my taste, but it should pretty easy to change.
This change has two big positive effects for me: First, it increases game speed by 10-40 fps, overall. (I was able to, on average, triple the number of trees - while keeping the same speed!) Second, it allows me to include up to 64 terrain textures, instead of 8.
Camera: I adjusted the rotation-to-zoom ratio. The end result is that the camera zooms in on the terrain a bit before rotating to landscape view.

Today I built many of the "detail" objects: Cacti, rocks, bushes, fallen logs. I got some practice generating textures for the cacti.
Current prop count:
* 6 cacti proper, 1 desert thorn bush
* 1 general-purpose bush model
* 1 "bunch of reeds" model, untextured
* 3 "Fallen log" models
* 4 large rock models, untextured.

Next: Finish texturing, and figure out a way to add contrast to the scene. Currently the visual "feel" of the game is a flat, bright "Age of Empires" appearance; I intend to darken the dark spots and brighten the bright spots and give the visuals some true contrast. I believe this will greatly help the visual feel. I may have to resort to a compositor, but I hope I can make do with less, as full-screen visual effects are (generally speaking) much slower than in my last engine. The current background image shows the effect I'm going for - deep, rich colors with vibrant shadows and bright glows.

For a speed comparison to my last engine:
Last engine, with reflections, grass, "deep ocean" effects, and trees: 15fps.
This engine, similar scene: 50-100fps.