Loaded up a game to take a look around and I like what I see.

First thoughts:
- Really glad to see the spark plug make its debut, as we talked about elsewhere.
- 'Logistics' research should probably have 'Electronics' as a prerequisite now, due to splitters needing the green circuits. Or change the splitter recipe. Though either way, red-only research goes so fast it might not matter too much.
- Are there common "normie" names for the 6061 and 2219 aluminum alloys that you could use? Maybe I'm just being dumb, but at first I read it as a quantity like, "I get six-thousand aluminum alloys from this recipe?! That can't be right."

Thanks for taking a look and thanks for the splitter note. I'll change that recipe in the next update.

As for the names, most Aluminum alloys are just numbered, there aren't really any historically named ones as far as I can tell. Technically, the number comes first. I honestly did worry about the quantity issue -- it does look strange especially since you can sometimes have like "10 x 70% Blah" quantities in factorio. So I had considered "Aluminum 6061 alloy", or "Aluminum alloy 6061" but elected to remain true at first. I'll consider switching to one of those for clarity.