Secret hero units:
Go to the Barracks, and select the "View Soldiers" option. Choose a soldier, then select the "Customize" option. This can also be done from the "Customize" menu at the "Deploy" screen. Change the name of the soldier to one of the following names to unlock the corresponding hero. These new heroes will dramatically improve the unit's stats, and they also have a unique
nickname. Note: Using these special heroes will prevent achievements from being earned.
- Joe Kelly (Heavy): Enter Joe Kelly as a name. Joe Kelly is a popular comics author that has worked on Spider-Man, Superman, and many other famous characters.
- Ken Levine (Sniper): Enter Ken Levine as a name. Ken Levine is the co-founder of Irrational Games, the developer of BioShock, Freedom Force, and System Shock 2.
- Otto Zander (Assault): Enter Otto Zander as a name. Otto Zander is the hero and survivor of GuavaMoment's XCOM Let's Play series from the Something Awful Forumes.
- Sid Meier (Support): Enter Sid Meier as a name. Sid Meier is the co-founder of Firaxis and creator of the Civilization series, Pirates series, and more.
Getting UFOs to appear in different countries:
If a UFO is spotted in a country you do not have much defense in or you want to lower panic somewhere else (by completing the mission to clear it), reload a previous saved game. The UFO should still appear, but it will usually be in a different location. You can keep reloading it until it is in a desired country.
Evil Crysalid terrorists mission:
During Terror missions that have evil Crysalid terrorists, you do not actually need to kill the Zombie Civilians to complete the mission. As long as all Alien forces have been defeated, the mission will end successfully.
William Carter from The Bureau: Xcom Declassified:
To unlock William Carter, the hero from Bureau: Xcom Declassified, go to your Barracks, select a hero unit, and go to the Customize option. Once there, change his name to William Carter (with William in the First name area and Carter in the Last name area). He is an Assault Class pre-equipped with Titan Armor, Alloy Cannon, and Plasma Pistol.