Everyone is counting on you. Literally.

Billionth Soul is an idle roguelite deckbuilder set aboard a failing generation ship. Begin with one thawed sleeper and grow humanity’s last colony to one billion souls before life support runs out.

BUILD THE LAST COLONY

Draft and place Habitat, System, and Program cards on a grid. Habitats grow the population, Systems reshape the colony, and temporary Programs create powerful combinations. Position matters: neighboring cards can strengthen, copy, accelerate, or undermine one another.

OUTRUN THE COLD EQUATION

Every new soul brings humanity closer to survival, but a larger colony consumes life support faster. Reach each population target to earn a fresh life support budget. Fall short, and the colony dies.

Vent life support for an immediate surge of souls when time is abundant. Scrub population to recover precious seconds when extinction is near. Every decision trades growth against survival.

ADAPT ACROSS RUNS

Recover Salvage, unlock new cards, and expand permanent research after every attempt. Build stronger strategies across interconnected research trees, complete 42 Achievements, and climb through ten difficulty tiers.

Winning strategies do not remain safe forever. After each victory, your strongest Habitat receives a penalty in the next run, forcing the colony to adapt instead of repeating the same solution.

KEEP GOING

Face a shared seeded Daily Trial, customize your board through research, pursue increasingly difficult victories, and unlock an endless expansion beyond the billionth soul.

You cannot save everyone on the first try. Learn, rebuild, and make the next colony survive.