I think the problem with ACM regarding "continuity" is that it flew too close to the original movies. I feel like Colonial Marines should've been a standalone story where it didn't make too many major events so it doesn't contradict anything. It could've involved another group of Marines that wasn't on LV-426, could've been just another Alien infestation. Maybe it could've been another colony built on LV-426. I mean, I love Hicks and I dislike Alien3, but I feel bringing back Hicks was a bit of a copout. I feel if they wanted to bring back Hicks, they would've just been better off retconning 3 and 4, probably would've been best to just leave him out.
Again, they should've just done a standalone story that didn't have any big connections. I mean come on, they expect us to believe that Hadley's Hope survived an explosion the size of Nebraska?
Course, I never consider videogames and books as canon, cause once they make the next movie, they get retconned. Like the Aliens comic books got retconned when Alien3 came out, and even more when Resurrection came out, and especially after Prometheus. Star Wars expanded universe anyone? Don't get me wrong, expanded universes are great for new ideas, but they'll only be canon for a short time. They always do.
One last thing and then I'll shut up. The instructions seem to say that you need Steam and Windows to get it to work. But I have a Mac. But I also have Crossover, which sometimes work. So if I buy this on Steam with Crossover can I play it? Or would I have better luck buying the CDRom and installing it that way?