StarCraft

Mission select:
Press Enter during a mission, type ophelia and press Enter. Then press Enter again and type the mission you want to play: terran0 to terran10, zerg1 to zerg10 or protoss1 to protoss10 (for example zerg6 for The Dark Templar). The mission select only works for the missions of the original StarCraft campaign, also when you play Brood War.

Secret mission in Brood War:
The secret mission "Dark Origin" is unlocked by completing the Zerg mission "The Reckoning" (Episode VI) with 5 minutes or more left on its timer, i.e. within 25 minutes.