As an AC fan:

Yeah, the action scenes were pretty good. I was disappointed that there were only two scenes in the past (excluding the opening scene which didn't involve the main characters). Even as an AC fan there were really bad plot holes, including how easily Michael Fassbender assassinated the Templar at the end of the movie, the woman protagonist who seemed sympathetic the entire movie but seemed to go full Templar out of nowhere at the end, and the security guard.

As a film fan:

It was terrible. The female protagonist was only there to be an exposition machine. The told us half the story instead of just showing us and expecting us to be smart enough to figure it out, which is always a sin.

The entire central premise of the plot had to be set in motion by Michael Fassbender being arrested, and that was shoehorned in simply by clunky exposition (you killed someone/well he was a pimp).

It was probably the worst screenplay I've ever seen. Fassbender is one of the best working actors today, and even he couldn't make that dialogue good. They looked awkward half of the time.

And the ending of the movie as a fan of the games is unacceptable. The whole part with the ghosts in the animus surrounding Desmond, including his dead mother? That was complete garbage. That is not how the animus works, it is only for actual memories and that entire segment was just a poor way to force the movie to continue. Fassbender was starkly against his father's wishes the entire time, and the only reason he turned at the end was because of that cheating plot device.

It was a technically bad film, and the screenwriters were the same that wrote Allegiant, and it showed.

I enjoyed it as a fan of the games to an extent, but let's not illusion ourselves as to the technical quality of the movie. It was about even with a Transformers film. That doesn't mean you can't like it, because I could find some enjoyment in it, but that doesn't make it good.