I've no issue with the redesign of the legs whatsoever. Heck, if I had been in charge of making this game; I would have made the same decision. Let's get something straight here; Ridley Scott's 'Alien' is my favourite film ever but when you finally see the creature in a wide shot (as it's blown from the shuttle's engine); it's clearly a man-in-a-suit. Yes, us fans can justify it by saying "that's because it inherited its human hosts DNA" but that doesn't stop it from looking a little silly (perhaps not to a seasoned fan such as us members of the forum - but certainly to more casual viewers). Just because I adore 'Alien', that doesn't mean that I can't recognise its flaws (after-all, no film is absolutely perfect).
Could they have stuck with the original design? Yes. Am I glad they chose not to? Absolutely.
Ultimately, it's all subjective but really; what does it matter? It's the most nitpicky of nitpicks. Also, when playing the game; you'll be cowering in fear from the alien. You're not going to be getting up close and personal to gawp at it's legs. You could always try I suppose, if you fancy becoming lunch.