As it turns out, Lyndon knows from whence he speaks, as his management and development experience stretches back to the original John Madden football. He also served in the ministry for many years before returning to the games industry, so he has perhaps a unique perspective for developing a Christian-themed game. And a ten year wait indicates that Left Behind Inc. wanted to make something more than a license cash-in. And from what we've seen of the game, Left Behind's games division is indeed serious about making a serious real-time strategy game.
Although the Rapture covers the whole globe, Eternal Forces will focus on Manhattan, albeit a painstakingly recreated one, as the Tribulation Forces (the good guys) are pitted against the Global Community (bad guys) in their war for the hearts and minds of those who were, well, left behind when the faithful went to the Pearly Gates. Despite living in the post-Apocalypse days, there is a legion of people who haven't chosen sides, and it's up to you to get to the neutral civilians before the Global Community does. (The single-player campaign can only be played as the good guys, but you can choose either faction in multiplayer.)
Rather than being a typical RTS warzone, the environment of Left Behind's NYC is relatively unchanged by Biblical events. For now, at least. You'll buy buildings and convert them to businesses, recruit civilians for various tasks, and gather people to your side by just walking up and talking to them. There are several unit types broken down into three levels. For example, the soldier unit appears as a basic military unit, then a "special forces" guy, then an elite soldier. Medics become nurses, who in turn become doctors. Your structure making units will start out as "builder," then "advanced builder," then foreman. So far, it's your typical RTS. But there are also units specifically designed to spreading your message, like the missionaries in Civilization IV. They'll start out as "disciples" and eventually become "saints," although it's not clear if there will be three miracles involved.
As you train up a unit, you'll improve its Spirit level, which you must keep an eye on against the many factors that will bring it back down. The higher the Spirit, the better the unit performs. If someone's Spirit is really low, they can be pulled to the Global Community's side. Although there are some nasty problems involved with eliminating all their spirit, chiefly opening a dimension gate that unleashes some unfriendly demons who will feed on those who summoned them if there are no civilians around. Whoops! So while you need to pump someone's Spirit, the GC will be working against your efforts, because they need people to have low Spirit to join their cause. And once you've gained that person, you'll need to continue to cultivate their Spirit. Perhaps appropriately, combat brings this down quite a bit, because killing people is kind of stressful. For the best results, you'll need to pump everyone's spirit level up before heading into battle, and afterwards. For the Tribulation Forces, this is done by praying for a few moments. The GCs curse instead (but it's unintelligible mumbling in the game). You'll also want to cultivate spirit because each of your unit types has a special ability that will come in handy. To reinforce the idea of these units being actual people, the incredibly prolific Chris Fabry has signed on to write individual biographies for every person you see in the game, and it runs into the hundreds. The main characters from the novels will also show up as "hero" units.
Last but not least, you'll come across scrolls and unlock "Tribulation clues" as you progress through the game. The former are objects found on the map that may provide you with money, other resources, or an angel to fight by your side, if your group's spirit level is high enough. The latter are 40 tidbits of Scripture information that Troy A. Lyndon has put together over the years. He gave us one example, which was a list of names starting from Adam and ending at Noah, names whose English translations suggested a meta-message when they were put in chronological order.
The game is careful to present these nuggets as interesting but potentially misleading; in fact, nowhere in the presentation did I detect any sort of "agenda" beyond them wanting to make a quality RTS set in the Left Behind universe. At the same time, they want to make units more than just cannon fodder for your tactical meat grinder, which is refreshing, if it works as well in practice as it does in theory. They also plan to release more content on a "quarterly" basis, such as more maps, units, and perhaps even a new city, given away free to the player base if it makes financial sense. Although I've never really got into the whole Left Behind deal, Eternal Forces looks like an interesting game, and one that doesn't evangelize like you might expect.