Viktor Antonov, the much-lauded designer behind Half-Life 2's City 17, jumped ship when Valve grew too large and stopped making the kinds of games he's keen on.
"Valve has grown into a much bigger company, and what I really enjoy about the philosophy of Arkane is that it's a small, core team that does risky creative projects," Antonov told Eurogamer.
"And when I went to Valve, they were a small company. They've grown now, they're much bigger, and I'm interested in a certain level of creative risk taking and a certain energy that can be compared to jazz, jamming or rock n' roll, where it's small, it's intense and it's about making revolutions in the media."
Antonov's last work with Valve was pitching Team Fortress 2, but he seems to have become dissatisfied with the company's non-traditional approach to development and release.
"I left precisely when they stopped making epic, triple-As, which was Half-Life 2. Since then, they were episodes," he said.
The designer described Valve as a "great place" but said it's projects that capture his interest rather than specific teams.
"I went and I collaborated with Arkane to do The Crossing and Dishonored. I put the project above everything else," he said.
Not that the creative has been entirely devoted to Arkane's first-person adventure, which hits PC, PlayStation 3 and Xbox 360 in October; he's also worked on films, TV and an illustrated novel since parting ways with Valve. He's now Zenimax's chief visual design director, overseeing work at the publisher's various studios, including Bethesda and id.