XCOM: Enemy Unknown

The player's goal is to complete a series of missions where they command a small troop to defeat the alien forces. Between missions, the player must manage the larger management aspect through research and development to create new technologies and weapons using captured aliens and technology recovered from the missions. The player also needs to keep panic under control, as neglecting certain regions can lead to reduced funding for XCOM.

For missions, a squad of four to six soldiers is selected from a pool of about twenty. Missions are set in small areas centered around a specific building. The game features a 3D isometric-style view with a fog of war that shrouds most of the environment until the soldiers uncover it.

The action is done in turns, and percentages are used to determine how successful actions are based on the soldiers' abilities and positions. Terrains can be fully destructible, leading to situations where new cover needs to be sought or the strategy needs to be altered after a part of the environment has been blown up.

The game features a variety of promotions for soldiers based on their actions in their first mission, which opens up access to special support abilities and additional weapons. Soldiers can also be fully customized in appearance, abilities, and loadout. The game includes 70 missions, some of which are pre-built, while others are randomly generated based on the player's overall progress.

The campaign can be played in Ironman mode where the game cannot be saved during missions, or in one-on-one multiplayer games with a mix of humans and aliens in a single squad. The game also features an inventory system, time unit system, and grid map that is always visible.