early game i just make a ton of grenades (which are kinda cheap and easy to make) and a car; then I just drive around the nests throwing grenades and shooting them down, usually ignoring the worms until I can deal with them later

it worked really well so far

Found out what's causing it: apparently railworld preset reduces the size of enemy bases, from 100% to 50%, making some achievements unobtainable.

This didn't happen in 0.16. For some reason it's happening now, and I'm pretty sure it has something to do with how railworld disables expansion.

That's it. ^^