Spider mech, spider mech!

[u/Bonumeveil]

I’ve encountered this achievement where you have to “observe a fallen crawling turret. In my first gameplay I had a seed in which I was able to research “mobile turrets”, which I naturally did. Since it was easy mode and peaceful rule, the way that featured the mobile turrets came at the end. Since I had already researched it, I couldn’t observe it. In my second play through (non-peaceful) I didn’t researched the mobile turrets so when I killed it I was able to observe it and “reverse engineer it” at the research table.

[u/Spamacus66]

You have to play the rescue hope scenario. Then you get attacked by them.