In Apollo 18: The Moon Missions, the player takes on the role as commander of the United States Apollo moon-landing mission. The game features two CDs, each specifically targeted at one of two main phases of game play. Nearly half the 200-plus page manual and one CD is devoted to the stringent Apollo astronaut training program while the second half of the guide and the other CD focuses on the actual moon mission of the Apollo 18 Taurus Littrow.

The space flight simulation contains three difficulty settings: rookie, pilot and commander. Each level requires the player to take a written computer test that includes both background information and hardware orientation. Only the Commander level results in landing on the moon and subsequent liftoff for the return to Earth. Missions are scored on specific criteria (nine evaluation areas) and successful completion of each leads to more difficult and comprehensive training sessions and missions.

Apollo 18 features full motion video, actual spacecraft module sound effects, 3D animation, variable mission outcomes (30 possible), eight training simulations, full command center spoken guidance during the actual moon mission and random space flight events. Complex game play challenges the player to gain full knowledge of the Apollo 18 flight plan, the command module, the lunar module, the Saturn V rocket and the Kennedy (mission) and Johnson (training) Space Centers.