Alien Isolation - to my knowledge... Just expanded on her daughter's story. Was there something else added that contradicts anything in the Alien films? Apart from the idea of the Company lying to ripley about her daughter. Cause that's not the same thing as a retcon.
Burke had no reason to lie - and Ripley had every reason to look up her daughter's life details from non-company sources. She would have been at her utmost paranoid about trusting the company at that point. Finding out Amanda went off in search of her voice recorder to somewhere which came to grief, Nostromo-style, would have been a big red flag.
And the fact nobody's heard about anything remotely like the Alien... Nobody mentoning that the woman's daughter mentioned encountering something similar, at Ellen's own hearing? Not plausible.
And if the company was nefarious and evil, having a reason for covering it up, then they would have also had every reason to go and seek out LV-426 and actively scour it before Ellen returned. They didn't. It's just another colony to them. One which they never bothered putting any real dedicated bio-warfare personnel or facilities on.
The game's really well presented and worthy of being praised, but even its own writers copped out of providing an explanation for Amanda's inclusion.
So, again, if people can take that gaming experience to heart, they can enjoy a movie which retcons the third/fourth movie, too. 'Isolation' proved that, so well as something is done well, people just won't care.
To be fair, all of those "continuity" issues you bring up can all be explained away really, really easily.
Amanda's fate in the game and her fate in 'Aliens' don't line up, but the game ends on a massive cliffhanger so there's obviously more story to tell, and dozens of ways to tie it all together.
W-Y didn't scour LV-426 for Alien stuff because they didn't know it was there - you shut off the Derelict's beacon in Isolation, and all other data from the Nostromo incident was destroyed (or floating in the Narcissus, awaiting pickup decades later). Even the crew files in the inquest in 'Aliens' mention the Nostromo case had been closed years after Isolation is supposed to take place - W-Y had simply stopped searching. It was obviously getting to be cost prohibitive - they'd lost the Nostromo, and 15 years later they lost an entire space station
, all with absolutely nothing to show for it.
I mean we're not talking Colonial Marines degrees of continuity speedbumps here.