We made the sandstorm with a shader that is getting fed a noise texture. It deforms that texture over time really fast, and with a yellow tint, it looks like a sandstorm! We're planning on making this game open source soon too, so I guess you can see that better there.
Also, sorry that it might be a bit slow to start. I was thinking maybe in a future post-jam update we could make configurable how fast the countdown is, because after you get used to it it kinda feels slow.
Thanks for your review! Vector and I will start voting soon together. Exited to try your game!