As it turns out, some of September was dedicated to preparing for the game's initial announcement and piecing together the accompanying trailer. Other than that, though, the devs did make a bit of progress on gameplay proper. Action mode combat was the biggest addition, and the update describes an interesting mechanic that allows users to "toggle between action- or RPG-mode combat at any time during gameplay."
The other big addition is The Repopulation's military system. In a nutshell, it's a ranking system that allows players to gain military XP while performing various duties for their nation's armed forces. Ranks, medals, and perks like armor, weapons, vehicles, robotics, and special abilities are among the system's rewards.