The Potential Was Lost Here
This sector feels like an afterthought when weighed with what was released in the mid-sector release of Sector 2. Personally, MyM had a great shot at amping up the traps here, but instead released what feels more like .25 of what could've been a 1.00. If you're going to do a toxic/radioactive biome:
1) Toxic Sludge Mod: A Corrosive Cube Mod, this is a toxic liquid variant but has a pool of GREEN viscous liquid that appears as though something is swimming in it, as it sloshes about of its own accord. The same rules apply when combined with other mods of the corrosive cube, including spewing toxic slime (which gives off a smoky vapor to indicate the lethality) hardened, opaque, etc.
This would have cost nearly nothing considering it's just adding a color variant to the corrosive cube, along with a minor animation addition.
2) Poison Chamber: a trap that is just a switch that has to be placed in a cordoned-off area (room must contain 6 walls, and cannot be too large, however mods can change the scaling of the noxious gas that fills it) once the custodian steps on said switch, a stone slab wall drops, encasing them, causing a countdown to begin; the raider must find the master switch (which must be placed within a certain radius of the slave switch during building, or conditions are not met and no switch can be placed) that once triggered, causes the tomb door to become salient, and allow the raider to shoot the door with any weapon to cause the door to open and let out the noxious gas.
Traps can be set in this room, allowing for more creativity. arc barrier, lodestar shield and future defensive weapons delay the countdown, allowing the raider more time to find the master switch.
I admit, this one is a bit more of a layered situation, and thus tricky, but I am sure there's a dev saying, "we could totally do that."
3) Radioactive Waste Barrels: These can be raiders of the lost ark in style, but the barrels are fundamentally basic in nature: when range is triggered on trap, one, or two (or even 3 as upgrades) barrels roll out of control toward the raider. these barrels must be built on declines only, as gravity is what makes them dangerous. as they continue to roll, they gain momentum and speed. The only way they can be stopped is if they roll out of bounds, or hit a wall to stop them, but the wall option only causes more mayhem: the barrels explode and its contents splash in every direction, ending as lethal toxic pools the raider must avoid. after a certain amount of time, the sludge left behind by the barrels dissipates along with the pieces of the barrel, as if nothing ever happened.
Anything in the path of the tumbling barrels is subject to the same treatment. guards, traps, and custodians, are all not safe, including anything standing at the terminal point of the barrels when they explode, and including the sludge that is ejected from them.
This one sounds just like a blast to design, also, rolling boulders is a concept this game desperately needs, to add even more quick thinking to the mix.
4) Poison-Tipped Darts Mod: A mod that can be applied to any or all of the traps that have sharp tips to them. these are just about cosmetic appeal, and for the veterans out there that have everything purchased, just a little more for them, and for everyone else. the element here is give traps variance in colors/theme to them. the poison dart mod can have green shining off the tips of the barbs of the traps, while also emitting the vapor/smokey look, and also give off a "hiss" sound.
Another easy cosmetic modification.
These are (again) some of the ideas relating to THIS sectors theme. My idea of Voltaic Outbreak (the addition of electrical components, and an imposter wizard creating "magic" was my other idea) brought a thematic set of traps to it too, and in all of my ideas so far, the release of a new sector meant at LEAST 3 traps/mods.