A two-mission demo for upcoming strategy game XCOM: Enemy Unknown hits Steam today.

A two-mission demo for upcoming strategy game XCOM: Enemy Unknown hits Steam today.

The two-tutorial-mission demo introduces players to the XCOM base, where training and research takes place, and gives players a chance to check out some strategy game play as well.

The demo will be available for consoles soon, publisher 2K Games said today, though they didn't give a more specific date.

XCOM: Enemy Unknown's pre-order bonuses continue to grow on Steam as well, approaching the final bonus which grants pre-order customers a free copy of Civilization V on Steam. Currently, tier 1 and 2 rewards are unlocked and that final reward is about half unlocked.

The first two tiers of pre-order goodies include the iconic flatopped marine from the original XCOM, new aesthetic armor kits, color tints and three customization items from Team Fortress 2 to apply to your away team.

Rewards unlock as more people pre-purchase the game on Steam.

XCOM: Enemy Unknown hits PC, PS3 and Xbox 360 on Oct. 9.