A single playthrough of XCOM: Enemy Unknown can take roughly 20 hours to complete on Normal difficulty, and even longer if you’re constantly reloading the game or taking your time to make your decisions as you play through it. It was rumored for awhile that completing the game would unlock a “Second Wave” set of options that would allow you to tweak the gameplay in future playthroughs, after some enterprising players dug through the files and found references to it.
These advanced gameplay options include “Damage Roulette”, “Red Fog”, “New Economy”, “Not Created Equally”, “Hidden Potential”, “Absolutely Critical”, and “The Greater Good”. It’s hard to tell what any of these options do, as completing a playthrough doesn’t actually enable these options.
2KGames’ community manager 2K Greg made a post regarding the Second Wave to clarify what it is after questions about the feature surfaced on the forum. He wrote:
The "Second Wave" settings that some people have found by digging in to the game files was a feature that the team was toying around with, but it was not ever finished by the time the game released. It’s something the dev team at Firaxis is still interested in going back to and working on, but at this point we don’t have any firm plans to share.
It will be disappointing if the feature isn’t added back into the game at some point, as it would most certainly breathe extra life into the game for players looking for an additional challenge.
XCOM: Enemy Unknown is currently available for the PC, Xbox 360 and PlayStation 3.