Can you guess what the mod does?
It adds defence systems (as the name probably implied).
This includes automated turrets and stuff like that, allowing for a devious set of traps and whatnot. But don't think it'll be easy to make...
It also includes some NPCs, armor, weapons, tools ect, but it mostly focuses on the defences.
There are many things to make each with variable "tiers", higher tiers are usually better and are tougher to make.
Machines are needed to make almost all of the things, because it makes things interesting.
So you're just going to take a couple of things and use the crafting table- Hah, no. You can't hand-make stuff like this.
This's incomplete, I'll add things as I think of them.