Firaxis recently upgraded its alien-hunting strategy title with an expansion that added more nail-biting decisions to players' plates. We spoke with XCOM: Enemy Within lead designer Ananda Gupta about how the team built off the XCOM system without breaking anything.

Game Informer: After you released XCOM Enemy Unknown did you have a list of things that you wanted to go back and address with the expansion?
Ananda Gupta: The two main things we wanted to add in Enemy Within were some new ways for soldiers to improve, and some new gameplay on the strategy layer that gave more control of the pace to the player. The Enemy Within theme fit both of those very well, so the game felt very integrated from the beginning.

Where did the idea for Meld come from; did you specifically want something that would force players out of their move/overwatch strategy?
We knew we had to add a new resource as a control on how fast the player can build the MECs and gene mods. It was important that these things get unlocked very early in the game, but a cost to that is the risk that players will over-adjust and build the new stuff too fast. So we knew we needed a new resource. Then the problem became: How does it unlock? Everything else already has a niche: corpses allow autopsies; weapons are their own reward unless they blow up into fragments (and even then they’re useful). Adding Meld as a sort of treasure recovery made a lot of sense. The timers then came into play because we didn’t want Meld to be the focus of missions, and if Meld isn’t the focus of the mission the pressure to recover it has to be separate from the pressure to do the other things the mission requires. Time pressure made a lot of sense. When we saw how it altered playstyles, we knew we’d hit on the right mechanic.

The MECs are a great new unit. Did you have trouble developing a new class that could offer something new without making one of the other unit types irrelevant?
The class design in Enemy Unknown actually left the door open for a new class focusing on area control; while this isn’t the sole purpose of MECs, it was a neat active role. Also, a class that doesn’t use cover was a natural add, since cover is so fundamental to the rest of the XCOM lineup. Given these differences, we were able to come up with a lot of different abilities, and pick the best ones.

The Seeker is an interesting new enemy. Were they mostly a response to players who like to camp snipers on one side of a map?
They were mostly a response to my desire to have an invisible enemy that strangles fools. The fact that they make snipers scared is a bonus. But there’s a lot of counterplay to Seekers; with the right kit, even snipers will learn to fear them less.

Conversely, the Mechtoid seemed like a lighter version of the Sectopod. What niche did you feel they filled?
I think he makes Mind Merge a lot scarier in the mid-game. Mind Merge didn’t offer any kind of improved benefit as the game went on in Enemy Unknown; letting the Sectoids get a better unit that benefits a lot more from Mind Merge helped round out the alien lineup. The Mechtoid is also a bit more flexible than the Sectopod since he can split his dual attacks.

Covert operations were a fun addition to the game, did you ever consider letting players control the missions where a single unit infiltrated Exalt?
We did consider that, but the missions simply took too long and were too dicey. The pace of the game is really different with only one soldier, especially if he or she is under-armored and lightly armed. It just made more sense to bring in the full squad.

It seems like there is still some issues with line of sight, in terms of enemies being awarded cover even when it looks like they shouldn’t have it. Did you think this complaint was fair, and how did you address it?
Flanking bugs are super irritating to us as well as to players, not just because they are an instance of the game breaking a basic combat rule, but also because they have many causes – offset terrain objects, bugs in the line-of-sight code, etc. This large number of causes makes it very hard for me to promise they are all gone, since I can’t point to a specific place in the code and say, “Okay, that’s where the problem was, and now it’s fixed.” I really appreciate our fans’ patience on stuff like that, and we’ve made a huge effort to eliminate them.

What issues were you hoping to address in this expansion, but didn’t have time to accomplish?
The biggest time crunch we faced was on cinematics, and we’d have really loved to do a new opening movie. Unfortunately, given all the other movies and camera sequences we wanted to do, we had to shelve plans to expand and re-shoot it. But in general even I was surprised at the number of areas we were able to “touch up” – we even fixed up the panic system some, so friendly fire is less common, and we simplified the “streak buster” logic in the random class selection system, so players will always be protected from a total shortage of a given class. I think we were able to strike a great balance between all the different kinds of new content we added and incorporating fan feedback and experiences into a second round of polish and I hope XCOM Commanders enjoy the new challenge.

If you haven't played XCOM: Enemy Within, read our review to find out why you're missing out, check out the game's interactive trailer to get a sense for the difficult decisions the game throws at you, and check out our online hub to learn all about the original XCOM: Enemy Unknown.