This movie doesn’t suffer from the bug that has plagued previous video game adaptations, in that the stories are less believable because of the change from an experiential medium to a passive one. It’s just a bad story.
I’m a huge fan of the game series, though it notably peaked with the Ezio saga in Italy and hasn’t been able to recapture the combination of storytelling and wonder that made those games great.
With that said, the movie adaptation is just bad. Let’s put aside the audience having to believe you can enter a machine that lets you experience your ancestor’s memories. Even after buying into that suspension of disbelief, the movie still doesn’t play by its own logic.
It rushes through plot points. It glosses over character development and backstory. It breezes through the very vital character development where Michael Fassbender, who initially doesn’t care and doesn’t know how to be an “assassin”, learns all he needs to know from an imaginary version of his past self “visiting” him over the course of a few minutes. And he learns to care with a single vision of someone at the end of the movie. That’s it. 0-60 in probably 3 minutes of screen time spread over two scenes.
The movie would have been far better if Fassbender’s current self learned about the Assassins and trained with them while experiencing his past self. Have both characters grow simultaneously. If screentime is a concern, you could accomplish it through various montages and it would be believable.
In The Matrix, Neo learns everything he needs to know in Act 2 to make Act 3 believable. By contrast, Fassbender’s character putters around until suddenly at the end he cares. It’s a shame with the three credited screenwriters (Michael Lesslie, Adam Cooper, and Bill Collage) they couldn’t produce a better story.
At least the action is decent when we are seeing his ancestor’s memories in old Spain. So if you’re a fan of the games and stuck on a plane for 6 hours, you could find worse ways to pass the time.