Why Game Trailers Never Show the Actual Game

The trailer for the video game Assassin’s Creed: Unity starts with a bird’s eye view over a packed city square in Paris, 1789. A revolution is at hand here: A poverty-stricken boy sobs as his mother is beaten by a castle guard; a chambermaid fights off the sexual advances of a nobleman. As a low-voiced monologue intones incitement to revolution, a mysterious league of assassins emerges from the shadows to slice the throats of royal guards, leap en masse from rooftops, burst through lace-curtained windows, swing on ropes through high glass windows into an ornate ballroom, and overturn a white-and-gold carriage with a noblewoman inside. “A tidal wave of change,” promises the monologue.

You’d never guess from the gorgeous animation of the trailer that the game itself would end up a glitchy mess that could hardly be played without crashing. Characters sometimes showed up without a face, or with their legs on their heads; the protagonist had a troubling tendency to defy gravity and fall upward, into the sky, or to fall through the floor into a featureless abyss. Ubisoft had to release a patch a month later to fix the all the bugs left in the code.