GG! Only pop. 178 to finish the castle is very good result in accomplishing the Demo.
In this game, most of time you lose to bad RNG, and when not, it's the game crashing to a memory insufficiency with Pop. 1500-2000+ kingdoms long after the completion of the castle and the demo.
I have no accurate statistics to show, but for every pop. 1000+ games there must be at least 20-30 games ended to a bad RNG very early in the game.
The most usual end result for me is population 18, or less.