Fireaxis Games has today announced pre-orders for the long awaited strategy title, XCOM: Enemy Unknown, albeit with a small twist to your usual method. Pre-ordering the game on Steam will net you the title, however people looking for those little extras will be surprised to know that they aren't available just yet, on Steam that is.

According to the store page, extra pre-order incentives will slowly be unlocked with more people pre-ordering, with three packages available at different checkpoints. Each pack has something significant to hope for, including the final tier that offers a free copy of Civilization V.

If you are a fan of Team Fortress 2 items and/or free video games, you’re in luck. The folks over at Steam are running a pre-purchase rewards program, and it works like this: If enough people pre-order XCOM: Enemy Unknown , they will unlock 3 exclusive XCOM-themed items in Team Fortress 2. If even more people pre-order, they will unlock a free copy of Firaxis’s other big title, Civilization V (and yes, you can gift it to a friend if you already own it).

While this is obviously a great incentive for many to work towards, the purpose is slightly defeated by other digital and store pre-orders offering the Elite Soldier Pack without having to hope for enough sales. Though this is obviously a great marketing strategy for Steam and Fireaxis, keeping an eye on the progress might net yourself a free copy of Civilization 5.

System requirements for the strategy title have also been released today, while nothing as high-end as Crysis 3 will require, a somewhat good system will still be recommended for smooth playing.

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

For more info on XCOM: Enemy Unknown you can check out our game page, or head over the Steam store page for a view of the current pre-order status. To find out where you can pre-order the game, check out the official page.

XCOM: Enemy Unknown will be available for PlayStation 3, Xbox 360 and PC on 12th of October.