XCOM: Enemy Unknown lead designer Jake Solomon has been keeping a secret.

Game designers are good at secret-keeping, of course, but Solomon has had an ace up his sleeve for a while, and during our visit to Firaxis' Maryland studios last week, he finally got to play that ace. XCOM: Enemy Unknown, Firaxis' highly anticipated strategy game, will ship with online multiplayer. In fact, the game was planned from the beginning to have multiplayer--and we had a chance to play it ourselves during the extensive tour.

Most notably, Enemy Unknown's multiplayer matches are generally quick and dirty, in direct contrast to the extensive single-player strategic marathons. Online matches eliminate the strategic layer completely, pitting two players versus each other in a single combat skirmish that's likely to last around 10 to 15 minutes. The setup is pretty simple: each player is given 10,000 total points to spend prior to the match on various units and inventories, and once the match begins, each player has 90 seconds to take their turn. (That's true of ranked matches, at least; you and a buddy can customize these and other options in unranked play if you want to experiment.)

The point limitation is the game's primary means of balancing, though Firaxis is abundantly aware that once the game is released into the wild, players might find creative ways to steamroll their opponents. There's good news in that regard: the studio can adjust point thresholds on the fly without patching, so if those cyberdiscs you like so much are overpowered (and a few members of the team suspect they might be), numbers can be tweaked without constant patches and hotfixes.

Oh, right: cyberdiscs. You see, you aren't limited to controlling human soldiers; your team can be a mix of human and alien units, each of which has some kind of weakness to exploit. Curious about what some of these units are, and how they behave? Take a look at some of the ways you can exercise your military might:

Soldier

These are the most flexible units in the game, as they come in various classes and can be outfitted in various manners. A soldier in a ghost suit can go invisible for a turn. Some armor types include a grappling hook, allowing the unit to gain a height advantage quickly. Archangel armor allows a soldier to fly for a limited time. Various weapons, armor, and inventory weapons add to the cost of your soldier, so outfitting a single unit as an armored angel of death could use up a sizable portion of your point allotment.

Sectoid

Sectoids are the weakest alien units, and thus come at a low point cost. They may not do a lot of direct damage, but they're capable of mind merge, which allows them to grant bonuses to more-powerful units. They can also lay down suppressive fire, which can potentially damage an enemy unit that dares wander in its path.

Sectoid Commander

As you might suspect, the sectoid commander is a beefed-up version of the sectoid, coming with more hit points than its lowly counterpart, and capable of a more effective version of the mind merge. The commander can also perform mind control, which allows you to take command of an enemy attacker. But the cost is much higher than a normal sectoid, given its powerful psionic abilities.

Click to page 2 to see even more units, and learn more about XCOM: Enemy Unknown.

Thin Man

Thin men are also relatively weak, coming with very few hit points and doing little direct damage. However, they can turn the tide of battle when used effectively. Not only are they highly mobile, but they can spew poison, in addition to annoying enemy targets with suppressive fire.

Chrysalid

The chrysalid is a fast, high-cost melee unit that has a very special effect on the battlefield: its human victims turn into dangerous zombies. In turn, those zombies turn into more chrysalids. Firaxis can't take total credit for the crazy visual design of the chrysalid; after all, chrysalids were present in the original X-COM. But they did an outstanding job on their version of this storied unit, and watching a zombie morph into a chrysalid is one of Enemy Unknown's grossest pleasures.

Cyberdisc

Cyberdiscs possess the ability to fly, making them completely invulnerable to melee-only units like chrysalids. Watching them in action is a treat: like previous games in the franchise, Enemy Unknown features highly destructible environments, and cyberdiscs are capable of bringing down walls, cars, and plenty more in a blaze of fire and debris. These hardy units are immune to psi abilities, do high damage, and perform a powerful area-of-effect attack called the death blossom. As you can imagine, cyberdiscs are the single most expensive unit in the game.

Berserker

Berserkers are strong melee brutes with a ton of hit points. Their most powerful attack is the bull rush, which damages any unit in its effective area. The berserker's high point cost isn't its only drawback, however: if your opponent brings nothing to the fray but cyberdiscs and floaters, you are simply a lamb brought to slaughter.

There are other units--floaters and mutons among them--and in our matches we tried various setups to see which would work, and it became immediately clear that the best teams were the most flexible ones, at least to a point. An all-berserker team might sound like a good idea at first, but without a ranged unit or two to back them up, a single airborne soldier could prove unassailable. Good strategies usually require some flexibility, to be sure, but don't discount the support abilities. In multiple circumstances, suppressive fire and overwatch (that is, a free defensive shot) proved immensely valuable, particularly when used by a cloaked unit.

We played every match with an Xbox 360 controller, and indeed, it was this version we played during our studio tour. This might come as a concern to PC players, who feel rightfully possessive of X-COM and its successors. Solomon reassured us that Enemy Unknown is in no way less deep or challenging just because it appears on consoles--and additional comfort came from none other than Sid Meier himself, Firaxis' director of creative development. Meier is the beloved designer behind Civilization, Alpha Centauri, and other renowned strategy games, and he's all too aware of the stinging criticism of passionate PC gamers. One of Firaxis' many goals was to retain the elements that made the original X-COM so memorable--and bring them to as many players as they could.

It's an admirable goal indeed, and there's no reason to think XCOM: Enemy Unknown can't erect the same tent poles that supported the original game. What we played left nothing but positive impressions, though snap judgments aren't the most valuable kind when it comes to games as long and involved as this. On October 19, 2012, the game's release date, we'll have a better idea of whether Firaxis' revival is as enthralling as the game that spawned it.