Nix looks around for a place to plant the muckroots. Unfortunately, there's no available soil around the floor. A few clods of dirt did drop down from the ceiling along with the sandstone mined out from around the oxylite, however, but it will need to be more stable to actually support plants. Plus, he has no water anyway. Nix continues digging what he can out around the oxylite, but only uncovers more sandstone and dirt so far. The floor is rapidly filling up with piles of raw material.
Mumble panics out of claustrophobia, holding his breath! He manages to do this while scanning the air around him with his multitool, revealing that CO2 is beginning to enter into the gaseous mixture alongside O2, the heavier gas pooling on the floor; not a threat right now, but if it rises high enough, it will be.
John gets to work excavating the cavern walls for space. Several hundred kilograms worth of loose sandstone later, he's dug out a space about a quarter the size of the main chamber.
Jobe listens at the walls for signs of movement, using his 'tool's built-in sonic seismograph to try and map any empty spaces through it. He is in luck: Above 17m, right 8m, down 21m, left 14m are areas with little enough resistance to the scan to possibly be other chambers. There's no telling what's in them from here, though.
A grinning, laser-focused Cath ignores Minecraft Rule #1, and digs straight down through the floor. The metal tile floor. The room is now filled with the fizzling sounds of digging beams punching two meter-wide holes into solid rock and steel at a time. Cath doesn't find any water this turn, but she does hit a layer of algae! The non-motile organisms are easily shredded into liftable blocks, joining the growing mass of raw material pooling at the bottom of the shaft.
Deciding to make use of all the loose sandstone gathering around, Khan activates construction mode on his 'tool and sets to work putting cohesive structures of parallel and perpendicular poles of compacted rock together, fitted snugly against the remaining tile floor below the oxylite vein. It's slow going, but it at least provides an easy route to reach more of the roof, so no one complains.
A hardy Duplicant named Bob steps outside the circle of noise and jagged rock and follows John's lead, digging out his own chamber extension into the wall. About half a minute later, he stumbles across a 'vein' of dirt wall, much easier going for his beam; but shortly after digging he spots a discolored shell-like object in the mass, which tumbles out of the wall, kicking its legs wildly -- wait, legs? Bob shuts his 'tool off quickly, staring at the crab-like creature while it scuttles upright, warbling and hissing madly at being disturbed. It has no eyes, and the only defining facial feature is a mouth filled with very sharp-looking teeth. While he watches, Bob sees the creature run in a random direction, bump into a chunk of sandstone, turn around, scoop the chunk into its mouth, and chew it apart with its teeth. It then moves on to another rock to eat that as well, while leaving behind a round lump of what looks almost like coal on the floor where its back legs were moments ago...
Upon noticing that Cath has discovered algae, Sgt. Giggles just about loses his shit in glee, for that can surely be deoxydized into breathable O2! He digs like a mad mole around her shaft, displacing the intervening rock to expose as much of the green colony as possible. All he needs now is a source of water and some electricity...
GM's Note: I think 8 is enough players for now. I don't think I'll be taking more until unless people start dying off. ^^