Andy Gilleand likes to edit games that have massive stories into full-length movies, and after doing it with the Uncharted series and Assassin's Creed I & II, he picked Assassin's Creed: Brotherhood as his next victim.
Gilleand created the movie by removing the in-game HUD and mixing gameplay footage with cutscenes. And, it seems, he did an excellent job. If you've got three hours, and you're not afraid of spoilers, you can watch the whole thing above.
Andy promised to do this with the remaining Assassin's Creed titles on his YouTube channel, but what's next? How about Metal Gear Solid? Oh wait...