In each level, the player must clear areas of Alien creatures and rescue survivors to progress. There are five Colonial Marines characters for the player to choose from and each has different skills and attributes. If the player's current marine is defeated by an Alien creature, the player must replay the level with another marine and has a time limit to rescue the previous one.
In each stage of the game, players must eliminate alien creatures and save survivors to progress. The game offers five Colonial Marines characters for the player to choose from, each with distinct skills and attributes. If the player's current Marine is defeated by an Alien creature, they must replay the level using a different Marine within a time limit to rescue their previous one.