2. Desmond Kills Lucy - Assassin's Creed: Brotherhood
Coming off the back of AC II, Assassin's Creed could do no wrong. The pacing of the game's sci-fi twist on real-world history was impeccable back then, and the second game had even ended on a supremely brilliant twist, breaking the fourth wall to address Desmond (and in turn, the player) by having the Goddess Minerva talk to him directly. For Brotherhood, we were expecting an expansion of this ideology, as both past and future were now intertwined - surely, the next step would be to set an AC game in the modern day, or at least address the fact that genuine Gods were now convening with us? Nope, Ubisoft decided to interject some sort of rivalry between these higher powers, making one of them really evil before forcing Desmond to kill Lucy through mind-control. How to fix it: Lose the 'argumentative Gods' stuff and actually go with the plan initially envisioned for the franchise, transporting it to the present day and framing Desmond as the time-taught Assassin he was always supposed to be. It's telling that AC creator Patrice Desilets left Ubisoft after this game, as this is presumably where Ubi's higher-ups stepped in and went "Oh... you were thinking of wrapping this up? We'll see about that." Brotherhood marked the high-point for gameplay and general quality of the experience for Assassin's Creed, but it would also be the first to really lose the purpose of the modern day story altogether.