2K Games has released a new developer walkthrough video for the much anticipated turn based  tactical combat videogame XCOM:Enemy Unknown. The video below is narrated by lead designer Jake Solomon who shows tactical turn-based gameplay mechanics along with some of the story elements. This is the same walkthrough which was showcased behind closed doors during PAX 2012.

The game is already available for digital pre-sale a month before than its 09 October release date. Those who pre-purchase the game they will get an exclusive Elite solider pack that includes all three bonus DLC's