The Earth attacked by superior aliens is of course a trope most made famous by H. G. Wells more than a century ago. The addition of aliens fighting amongst themselves, with some allying with us, is also something we've seen before. So are the mechs, recently seen to best effect as the toasters in Battlestar Galactica. A new component in this season's Falling Skies is the star child, a human-alien hybrid who grows more quickly than humans and has superior powers - last seen in the late lamented V on ABC-TV a few years ago.
The child in Falling Skies is Tom and Anne's, which raises the question of where she - the baby girl - is getting her powers. Possibly this has something to do with the time Tom was on the alien ship, in between seasons 1 and 2. Meanwhile, Tom's relationship with his three sons also continues to be well depicted, with Ben, the middle son who was freed from alien harness, still of greatest interest, though Hal's relationship with his former girlfriend, now a bad-alien leader, has potential.
The locus of the action has shifted from the road and make-shift headquarters to something more substantial in Charleston, where Tom has been elected President of a fledging United States. This makes for a refreshing touch with Weaver, now a Colonel, calling Tom "Sir," but the move to genteel Southern cities is also something we've seen in other post-apocalyptic dramas, including Revolution and even a bit in The Walking Dead. And a resurgent United States after the apocalypse also popped up in Revolution's season 1 finale.
So what makes Falling Skies appealing? It's the acting, most notably Noah Wyle as Tom. And with Gloria Reuben as Tom's aide and House's Robert Sean Leonard as an eccentric scientist (what else?) this season, I'm definitely in for the run.
See also Falling Skies Returns ... Falling Skies 2.6: Ben's Motives ... Falling Skies Second Season Finale
And see also Falling Skies 1.1-2 ... Falling Skies 1.3 meets Puppet Masters ... Falling Skies 1.4: Drizzle ... Falling Skies 1.5: Ben ... Falling Skies 1.6: Fifth Column ... Falling Skies 1.7: The Fate of Traitors ... Falling Skies 1.8: Weaver's Story ... Falling Skies Concludes First Season