Ken Levine first got into the game industry in 1995 when he joined Looking Glass Studios. At Looking Glass, Levine would develop his first hit, Thief: The Dark Project. Thief was a big hit with critics, many naming it one of the greatest games of all time. Thief would also be a commercial success for Looking Glass. Thief would be a large inspiration for future stealth games, such as Assassin's Creed.
Levine would eventually go on to found Irrational Games. Soon after founding the studio, Irrational Games teamed up with Levine's former studio, Looking Glass Studios to develop System Shock 2. Like Thief, System Shock 2 was a huge hit with critics, once again praising the game as one of the best of all-time. However, System Shock 2 would not meet the same commercial success as Thief, though it would eventually form a cult following. 3 years after System Shock 2, Levine would produce his next hit, Freedom Force. Freedom Force was a real-time tactical RPG that was seen as a respectful satire of comic books' Silver Age. Like Levine's previous titles, Freedom Force was met with many favorable reviews. Levine would then go on to develop his next hit in 2004, Tribes: Vengeance. Tribes featured an enhanced version of the Unreal Engine 2.5, called the Vengeance Engine. What separated Tribes from other sci-fi first person shooters was the use of jet packs, which became an important part of combat. Tribes was met with favorable reviews though was ultimately overshadowed by another sci-fi first person shooter, Half-Life 2.
The next year, Ken Levine developed the sequel to Freedom Force, Freedom Force vs. The 3rd Reich. In the sequel, the superheroes from the original travel back in time to battle the Nazis. Like the original, Freedom Force vs. The 3rd Reich was met with many favorable reviews. Less than a month later, Levine's next game was released, entitled SWAT 4. SWAT 4 was Levine's first attempt at a realistic first person shooter and like the rest of Levine's game, it was a hit. SWAT 4 was another huge hit with critics everywhere. In 2006 Take-Two bought Irrational Games, renaming it 2K Boston.
A year after being bought out, Levine developed his first game under 2K Boston, BioShock. Levine described the game as a spiritual successor to System Shock 2, which was apparent through its many similarities. Like System Shock 2, BioShock was huge success with critics, gaining many Game of the Year awards. Not only that, but the game was also a huge commercial success, selling more than 1.5 million copies.
Levine was not involved with the development of BioShock 2 but was credited at the end as a special thank you to "everyone who worked on the first BioShock". In 2010, 2K Boston announced that its returning to its original name: Irrational Games.
On March 26th, 2013 the Irrational Games developed sequel to BioShock came out, BioShock Infinite.
It is rumored that Levine is working a new installment in the X-Com series.
Todd Howard once tweaked Ken's nipple. He claims to have liked it.