Worst parts about the movie?

[tleilaxu]

When you make switcheroo keep it coherent. It's basics of script writing.

Switcheroo in Covenant is incoherent as hell:

When David leaves citadel he looks concerned. Audience thinks it's Walter.
David doesn't behave like Walter when treating Lope inside lander. Then why bother showing us concerned David (as Walter) few minutes earlier. Doesn't make sense from film-making point of view.
Then it's even worse: David's reaction when Xenomorph was running through Covenant's. We already know that's not Walter but it was cheesy. As I said before, they killed suspense and surprise.

Yeah. I think they were torn between either a) realizing that the audience would suspect from the beginning and thus not present it as a twist b) present it as a twist to shock the audience at the end
It ended up becoming a weird mix, where they almost tell you "It's David" but keep some things vague as if they were trying to fool you. I could've been solved pretty easily by just showing how the David/Walter fight ended. Hell, it would have been even more of a twist if Walter, loyal and dutiful Walter, killed David and then implanted his chip into himself due to Weyland-Yutani programming (this is kinda what I suspect happened).

[BishopShouldGo]

I'm just happy Ridley made an ALIEN FILM after all these years. Maybe to please both the Prometheus and Alien fans he could put Engineers and Xenos in the same film. Put half Prometheus and half Alien in a blender. I think people want the mystery and adventure of Prometheus tied with the terror, dread and gore of Alien. It was like Prometheus was too much Prometheus and didn't have any Alien while Covenant was way more Alien with little Prometheus. Scott needs to get the right blend. Ha, even maybe throw Sigourney in the mix for the hell of it and you might bring back the box office.

Or just write an amazing story that follows its own logic and is satisfying and of a piece within this universe. What you and Protozoid et al. get wrong is that it's xenos or Engineers or both or 30% of one or this and that. Whatever the story calls for, let it happen. Let the story be what it wants to be. The engineer and xeno stuff is a bunch of yada yada. It all comes down to the human characters. Branch off from them.

[Corporal Hicks]

When David leaves citadel he looks concerned. Audience thinks it's Walter.
David doesn't behave like Walter when treating Lope inside lander. Then why bother showing us concerned David (as Walter) few minutes earlier. Doesn't make sense from film-making point of view.
Then it's even worse: David's reaction when Xenomorph was running through Covenant's. We already know that's not Walter but it was cheesy. As I said before, they killed suspense and surprise.

I think you may have misunderstand that look back. It's a massive tell that it isn't Walter but it's David. It's not concern, it's that lingering connection to everything he's achieved on Paradise and it's such a huge tell. They just throw tell after tell at you.

[Ingwar]

I think you may have misunderstand that look back. It's a massive tell that it isn't Walter but it's David. It's not concern, it's that lingering connection to everything he's achieved on Paradise and it's such a huge tell. They just throw tell after tell at you.

I didn't think about it that way. You say it's not concern but connection to everything he's achieved. I buy that. But it also depends on viewers interpretation. It could have been Walter's concern look since he became less robotic after meeting David (flute scene and hesitation during the fight).