The maker of the ground-breaking BioShock video game is shutting down his studio to work on another project.

In a message posted on the studio’s blog on Tuesday, founder Ken Levine announced that he is “winding down” Irrational Games. Levine noted that Irrational Games had begun 17 years ago as a three person team operating out of a Cambridge, Mass., living room. But now he said his passion had switched toward “making a different kind of game” and he needed to “refocus my energy on a smaller team.”

With the end of Irrational Games, which will still release one more update for BioShock Infinite, Levine will launch “a smaller, more entrepreneurial endeavor” at Irrational Games’ parent, Take-Two Interactive (TTWO). Levine’s decision means that most of Irrational Games’ staff will be laid off. About 15 members of the studio’s team will join Levine’s new project at Take-Two.

Take-Two purchased Irrational Games in 2006. A year later, the studio released BioShock for personal computers and Microsoft’s (MSFT) Xbox 360 console, VentureBeat notes.

The BioShock games proved a hit with games, tallying up more than $500 million in sales. Take-Two’s 2K unit will continue to oversee the development of new games set in the BioShock universe.

Aside from BioShock and BioShock Infinite, Levine and Irrational Games also released System Shock, widely viewed as one of the top video games ever released.

TTWO stock slipped slightly in Wednesday morning trading. TTWO shares have climbed more than 30% over the past year.