XCOM: Enemy Unknown is more homage than imitation. While it bears a striking resemblance to the original 1994 classic, Firaxis has broken down the formula into its component parts and reexamined them piece-by-piece, building a game that retains its identity without feeling dated. At PAX, I got a chance to play the game and chat with lead producer Garth DeAngelis about the design process.

"Our mentality when we sat down to re-imagine the game, we defined [gameplay elements] as pillars. We said we need permanent death, we need a strategy layer where you can make these big sweeping decisions, we need turn-based combat," DeAngelis said. "But when we went back and made a prototype that was very similar to the original and play-tested it with folks who didn't play the original, we found that a lot of things were abstract and didn't really make sense to them.

"Game design has evolved in the past 18 years. We know streamlining can be a dirty word, we didn't want to water anything down but we did want to tweak some of the mechanics so as many people can pick up a mouse and keyboard or console controller and enjoy it. That was one of our goals, we wanted the learning curve to be a little more accessible."

It certainly felt accessible enough to me, years removed from the classic game. The demo included a gentle tutorial that outlined the movement and weapon options, then gave a few upgrade paths and choices. Chief among these were how to upgrade individual soldiers from a wide tech tree. The choices were limited, since the demo only spanned a very early portion of the game, but the branches clearly had plenty of room for customizing the team.

I did wonder, though, if that tailored approach would lead to problems if soldiers died. One of XCOM's defining traits is permanent unit death, and losing your best men could easily be frustrating. "We didn't want the challenge to be so difficult that it's unfair," DeAngelis said. "Obviously that puts you behind the 8-ball, and you'd have to do some work to get some of your new recruits up to speed. But there's also some mechanics in the game that encourage having not just one A-squad and leaving all the other rookies with no combat action whatsoever. Even if your soldiers don't die, they can be fatigued, they can be wounded. So you can't just put them in every single mission. Ideally, you'll have a B-squad."

Fortunately, you'll have plenty of soldiers in any event. DeAngelis said the game doesn't have any option to re-spec soldiers, but the game will feed enough squad members to try different combinations of upgrade paths. Even if your best squad gets wiped out, you'll be able to upgrade your rookies with non-story missions.

I was also presented with a choice to help a city in North America or China, knowing full well that it would upset the other. Each country in the council has its own panic level, which rises when you leave them on their own during the alien attack. Players have a tendency to min-max and seek an ideal playthrough, and I wondered if that would even be possible in a game like this.

"If you can make that happen you will be the first I have seen," DeAngelis laughed. "There's many losses in XCOM Enemy Unknown. It's part of the magic of the game, having consequences, odds stacked against you. Even on easy, you are very likely to lose members of the council. It's just something that's going to happen. You don't have enough resources to address everything at once so you're going to have to make tough choices, which is part of the game."

The result of those systems are a game that isn't precisely like the 90s title, but it felt right. It may be a little easier to get into, making it more welcoming to newcomers and console players, but the mechanics are in place. If it iterates on that potential, this Enemy Unknown will be just as complex and strategic as the original.