The color palette is sublime: evocative, draws the eye to detail, a striking balance of warm and cold. Cover art reminds of a 60s pulp magazine in the best way. Insectoid art is restrained; invites the viewer to form theories, but is not plainly protagonistic or antagonistic. I love using the chamber effect dice to build the obelisk; that creates very cool and clear mounting tension at the table level which could be represented in-fiction in a number of different ways. The premise is clear and invites a great variety of roleplaying opportunities.
Some notes, though all of them are picking nits off of an overall solid adventure:
CLARITY:
I was a little confused by the term “excav team” because it seems to be used for both the now-cultists as well as the human team of scientists.
It’s possible I missed it, but the connection between opening the chambers and powering up the obelisk seems arbitrary. Perhaps this was the best way to ensure a slow-burning fuse on the obelisk, but I think the adventure would benefit from some more connective tissue between this pivotal player action and the dire consequence.
The layout is a touch rough; I had to backtrack a few times for important context, and the font is smaller than it could be given how much white space you have left over.
MECHANICS:
The “gadget” should have a little more scaffolding around it, otherwise it feels like accidentally stumbling into a silver bullet without much strategy behind it.
I’m not sure what the “Oubliette” is there to do other than give the PCs nightmares. I’d suggest thinking about its function for the aliens and translating that to a few knobs and dials for the players to interact with.