Some of you dislike the fact the alien having two joints legs and at the same time wanting the alien to movie bipedly. and not quadripedly like we see it on "Alien Covenant".
But the fact is that if the you show the xenomorph walking bipedly with one joint its movement looks too much human and "man on suit", thats the reason why Ridley Scott avoided on 1979 to show full body shots of the xenomorph walking.
Even whe it was intended to film the xenomorph walking on a full body shot the made Bolaji Badejo, perform some kind of "crab walking" instead walking erected on his two legs (Thanks God it was deleted cause it´s laughable):https://www.youtube.com/watch?v=eR5jYeIMBKk
But if you take the Big Chap from "Alien" and give him two joints legs, you can show him walking without its movements looking too much human and without the sensation is a man in disguise. So for me the design on "Alien Isolation" is perfect: