Two things:
You sir, are mental!
And, REALLY?! As if they weren't terrifying enough!

Other than that, brilliant! Honestly too bloody scared to try it out myself but bravo mate. Have a cold one on me.

Thank you for your comment.

Originally, they fired full nuclear warheads, which had some different consequences.
1) Everything within a 35 tile radius where the nuke landed was destroyed, which meant bye bye defenses.
2) The behemoth spitter that launched that nuke would always be killed in that explosion, which meant that they would only be able to fire one.

I'm considering putting that back in, but instead of regular spitters firing them, having a boss spitter that rarely spawned. Anyway, it's fun seeing what happens if the enemy has the same firepower as you.

Time to set up self-repairing defenses!Or minefields!

New defense idea:Decoy perimeter(applies if the enemies fire regular nuclear warhead)
Decoy should be a cheap item.And it should be able to attract enemy attention.
In very late game,the evoluion factor should be almost 1.So there will be behemoth spitters in every enemy wave.
Set up a decoy perimeter consisting of decoys only.Then put a regular defense perimeter(with roboports) behind the decoys.Make sure the roboports can reach the decoys.
When enemies come,they will fire nukes at the decoys and destroy (almost) the entire wave.
If there are more enemies:The construction bots come out to place new decoys.Then any remaining spitter should fire at the newly placed decoys,or the robot(which is immune to the nukes).If there are no spitters left,the regular enemies will be handled by the regular perimeter.

The boss spitter would be a nice idea. Maybe you could increase the range of the spitters.

And please update the Mod to 0.16.