Some cool stuff here! I like the heavy faction elements and the megatroid PCs, though I think there's more that could have been explored with incorporating Mario elements - a pipe network seems like a natural fit.
The biggest area of improvement I see is the adventure leaves too much work up to the GM to round it out and prepare it to run. For instance: "Each tunnel should advertise its owners with three obvious clues and one subtle clue" - these don't appear to be in the entrance location keys; treasure needs to be rolled on tables; "draw a more detailed map" for the Dead God's altar; etc.
Perhaps a lot of this was due to the jam's time and space restrictions. I think if you could flesh out the keys with more detail it would improve things a lot.