I just got the achievement for this (make it to wave 30 on Settlement); it was pretty tough! Thanks to rabies for the basic loadout/strategy.
You can do this solo, but I played with a friend of mine. The difficulty scales, but I figured with both of us being fairly good players this was the best bet. The beginning is the hardest — once you get some sniper turrets set up, you’ll be gaining tons of scrap and won’t have to run all over the place, so don’t worry if it feels like you’re getting slaughtered at the start. By wave 15 our green base had only a sliver of health left, but we made it!
At least one person should have:
Core: HoneyChurch IV with Sprint+ Legs
Weapon: Albert Sniper Rifle (Pierce+)
Emplacements: Dampening Generator, Repair Crane, Sniper Turret, Shredder Turret
My friend used a bigger Trench with heavy weapons. Use whatever you’re comfortable with. He had a collection pod. If you’re playing solo, you should probably swap the repair crane for the collection pod. I mostly stayed up near the green base, and my friend stayed down near orange. Because I had the sniper rifle, I was able to help him out from up there.
- Start with all shredder turrets. They’re cheap, and at the beginning you need all the help you can get. More is better. Don’t waste scrap on other stuff yet (maybe a collection pod after a few waves).
- Scrap disappears after a while, so grab it when you can, and eventually build collection pods.
- Put emplacements on top of “trees.” I think you need to be on the lowest level for this to work (don’t be on a peninsula). Knobs shouldn’t be able to kill them this way, but watch for Burst Transmitters.
- Build lots of sniper turrets once you start getting more scrap, and protect them from knobs with shredder turrets. Place some snipers at the end of the peninsulas, and up by the green decoy.
- Focus all your fire on the Volt Dropper if you can! They do a lot of damage and ignore dampening generators, so you need to take them out as quickly as possible. Sniper turrets are what you need here, so I hope you’ve built a few by this point. When you fire at the Volt be sure to lead the target (aim a little in front of it when you fire).
- Save the decoys for waves 25+ (as long as you can wait, basically).
- Eventually build a repair crane somewhere in the middle, but not until you have plenty of scrap.
- Turrets are dumb, so kill Jacobs first, as soon as you can.
- If you’re using the Albert sniper rifle, try to line up multiple enemies when you can because of the pierce ability. If Jacobs are protecting an enemy, shoot through the enemy to hit the Jacobs; don’t wait for a clear shot.
We made it to wave 42 with this method, and would have gotten further if we had tried. After we got the achievement we relaxed and mostly let the turrets do the work, so eventually some enemies slipped by.