Today, 2K Games revealed XCOM: Enemy Unknown's system specs and a peculiarly designed pre-order deal on Steam . All of the pre-order rewards, which include a free copy of Civilization V, are not guaranteed: in a post yesterday, 2K said three tiers of incentives unlock as more pre-orders roll in, with purchasers receiving the accrued spoils on XCOM's October 9 release.

The first tier, the Elite Soldier pack, gussies up your squad with "several aesthetic upgrades to armor suits" using "a variety of colors and tints." You'll also nab a soldier sporting the classic flattop hairdo from the original XCOM.

Tier 2 inflates your overflowing Team Fortress 2 item backpack with a flattop hair-helmet (sans appropriate theme music , sadly), an "Area 451" Sectoid head-over, and a giant Vigilant pin.

The last tier keeps it simple: a free copy of Civilization V, which is giftable for those who already own it. As I write, the progress bar is at around 80 percent into the first tier.

2K has also revealed XCOM's system specs. In addition to packing in more tasty tactical treats for the PC version , XCOM's development team gratified the PC's "superior hardware" with increased detail depth and graphics power, but the below system requirements show support for a wide range of setups:

Minimum Requirements

OS: Windows Vista

Software: Steam Client

Processor: 2 GHz Dual Core

Memory: 2 GB RAM

Hard Drive: 20 GB free

Video Memory: 256 MB

Video Card: NVIDIA GeForce 8600 GT/ATI Radeon HD 2600 XT or greater

Sound Card: DirectX Compatible

Recommended Requirements

OS: Windows 7

Processor: 2 GHz Dual Core (Intel Core 2 Duo 2.4 GHz or Athlon X2 2.7 GHz)

Memory: 4 GB RAM

Hard Drive: 20 GB free

Video Memory: 512+ MB

Video Card: NVIDIA GeForce 9000 series/ATI Radeon HD 3000 series or greater

Sound Card: DirectX Compatible