There are a lot of creative ideas here, but I think usability is the weak point. Some things aren't well explained and the overall pamphlet doesn't quite make it clear whether it's an adventure or a setting. If you intend to keep working on this after the jam, I'd suggest maybe focus the trifold on the setting, and make a zine for the adventures to go with it. I feel like exploring the world, discovering its secret, and escaping the awakening are each worth at least a full session, and that's too much to approach with a single trifold.
The general look and design is good. Simple, but aesthetically pleasing and easy to navigate. The writing is more of an issue, often a bit unclear and seemingly off-the-cuff.
The most confusing part is T.O.M.B.S. Is each item there supposed to be a possible adventure hook? Or is it a sequence of events? If it's a sequence, how does it relate to the Apocalypse Clock below? Are they two different timelines that the Warden is meant to choose between?
The mites are a bit confusing. You say they're smaller than a speck of dust but that they grow rapidly off-world. Are the stats for the bigger version? Or for a swarm of them? If it's for a single speck-sized bug, maybe some explanation of why it's so harmful might be in order, because I can't imagine something that tiny causing potentially lethal amounts of damage in a few minutes just from burrowing into the skin. Overall, I'm not sure combat stats are the right way to handle that small a creature anyway, might just want it to be e.g. a Speed check to swat it, otherwise you get bitten.
Likewise the Pungee Pool isn't quite clear. The creature is just the vines? Are the stalagmites part of the plant itself, like thorns, or are they mineral structures it somehow induces to form?
Anyway, I like the idea and many of the details, like the spike colonies and the planet's whistling breath. Just needs to be tightened up and fleshed out a bit. A cutaway map of the Bottleneck's levels would be a great addition.