Bitloop

Your drone orbits the vault core and fires on its own. You only steer  the circle which way it spins and how tight it cuts. Ride close and the outer ring shreds in seconds, but a missed read costs your hull. Ride wide and you'll outlast anything, but you'll be down there a long time. Every vault is a question of where the line is.

CRACK THE CORE, DROP DOWN
Strip the outer ring of debris and defenders, then break the core  underneath. The floor opens and you fall into the next vault. Each one is denser than the last new core types, harder break patterns,  new biomes with their own hazards. The deeper you go, the better the haul, and the meaner the floor.

EVERY RUN MAKES THE NEXT ONE LOUDER
Everything you tear loose comes back up with you. Spend it between  runs on upgrade cards fire rate, hull, orbit precision, magnet  pull, crit and a full skill tree that rewrites how runs play.  Nothing is wasted. Every run pushes the floor down a little further