I watched the first two episodes of Alien Earth, too.
...I'm right on the edge of liking it and not liking it.
I actually think there's a interesting enough sci-fi story idea in here. The stuff with the siblings is actually kind of interesting. But, it almost feels like it doesn't have much to do with "Aliens" at all. It's like they had a script for a sci-fi show or movie and just added the Aliens in after the fact.
Between these two episodes, there's only about...7 minutes of actual Xenomorphs here, over the span of about 2 and 1/2 hours. I was actually a little confused when the other aliens started showing up, because I thought they were just facehugger-variants that I had missed from one movie or another or something.
I do like the high concept of the Xenomorphs finally arriving on Earth proper after all these years. For a franchise that's been going on this long, I think this is fair territory to travel down. They haven't done much with it yet, but maybe as the series goes on, it'll get more interesting on that side of things. Though, I'm not sure how far they can actually go, since this is technically a prequel to the first Aliens movie.
The first episode is also pretty slow, and I'm not sure if I like how it's edited. It's...fine, probably. But, it feels like it's chopped up just for the sake of doing things out of order with the flashbacks. The rock songs they're playing over the end credits are fun, but really don't feel like they fit the tone of the show.
So, this is fine, probably. Most of my problems mostly stem from budget-related issues. It's hard to do a Aliens TV show when you can only really afford to show the actual Aliens themselves for a couple of minutes per episode. They're doing their best. I'm just not sure if I like it. But, this is probably about 8 episodes long, so I can probably just keep watching it. It's not that much of a commitment.