I found the mod, but decided to go with the fresh start variant that I don't think is made by the same person?
Regardless, I really love the core idea of Arig. Sand-sifting especially, and I had a lot of fun even if the early game was slow. A few complaints incoming, followed by some ideas/suggestions.
Although the sand-sifting is a fun concept, the ratios of resources, their yield, and the byproducts is pretty skewed. I ended up with maybe 40-50 sand sifters and that gave me maybe one and a half yellow belts of iron. Meanwhile, it both drank ludicrous amounts of sand, and spat out hilarious amount of pure sand. Without tanks, it was horrible, and even with tanks I needed to empty them manually far, far too frequently, and I couldn't find any better method of disposal. (Turning them to bricks and chucking said bricks into the sand wasn't feasible, even with my modest production.) I think increasing the amount of sand required for bricks and/or glass might be helpful.
The steam situation was also an issue, though far less of one, and one I suspect playing as intended and arriving with lots of research and power-hungry buildings would've improved upon. Though I suppose a lot of that steam would go to water. I couldn't get water with my modded variant, lacking the research, and had to make myself a little well via map editor to crack down the heavy oil. I saw someone having issues with that steam to water ratio in another thread, so perhaps you're already well on that.
Alrighty. Done whinging. Here come a few ideas.
I really love the barren landscape, but it is a tad uniform. I'm not sure to what degree it's possible (or realistic) to add stuff like mountain ranges once one gets to X distant from spawn, or huge open desert areas, perhaps with assorted dangers and rewards. I do think rewards beyond heavy oil (fairly common and easy to find) and the crashed space parts, it'd be fun to have more to look for in the desert.
Monsters: Maybe traversing onto the softer sand draws out bugs? Or some other enemy. It'd make exploration spicier.
Water and vegetation: On a planet where water is scarce it would be interesting to have a mechanic revolving around water. Maybe some kinda reverse solar-panel mechanic wherein you gather moisture on the building over the course of the evening, and then you get a little bit of water as morning comes along (for the early stages), then wells, then perhaps drills to find underground lakes.
We've already got glass, so maybe something utilizing stuff grown in greenhouses. (I realize this may not make sense if it's a hot planet, cos then it'd be even hotter, but some sort of contained and cool-ish place that can retain moisture and let stuff grow.)
Some kind of use for sandstone along the lines of building paths along the islands. Maybe with the stipulation/limitation that only belts and pipes can be built upon these paths since sandstone isn't exactly the hardiest material. It'd allow us to expand to nearby islands in rudimentary ways in the earlier stages of the game before we get foundations and can build trains.
I'm really looking forward to seeing where you take this mod. Stellar work so far. :)