Playing my second game of this, on the easiest "starter" level and things are ticking over with only a few problems here and there, mostly related to worker dissatisfaction and lacks of essentials etc. Suddenly: colony explodes! Game over.

What happen? A bug? Did I overlook something super-important?

Pretty sure you forgot something or some enemy action put you out. Another asteroid may have crashed into yours.

Yeah, if your colony runs out of a critical resource or the CPU dies, so does everything else.