After a short single-player tutorial, 30XX begins with players taking control of a newly awakened robotic life form. A beautiful mad scientist has apparently awakened the heroes and challenged them to either stop her from destroying the world or die trying. From there, players emerge in a lobby from which they can switch characters, talk to NPCs, join co-op games, start a run, and more. The game can be played in Roguelike Mode or Mega Mode, the latter of which provides a more traditional experience without permadeath.