According to one source, each new lead and senior designer would come with a new vision for the game. Old ideas — including stages and mechanics — would be rebuilt or scrapped. In March of this year, the same month as the game's publicity push on the cover of Game Informer magazine, Lead Game Designer Dominic Fleury left the studio. The studio has seen a number of high-level departures
Sources emphasized the high level of talent and enthusiasm of team members, many of whom came to work on Thief because of their love of the franchise. Those same sources cited team politics and conflicting visions as cause for many departures and setbacks.
Due to a need to hit promotional deadlines, the latter part of 2012 and early 2013 was focused on creating press demos, the first of which was shown for the Game Informer cover and also at last month's Game Developers Conference. According to a source, the demo took nearly 10 months of development time, roughly six of which required the participation of nearly every content creator on the team. The level, which takes place in part inside a brothel, apparently featured "Cinemax-level" sex sequences at one point that some animators were uncomfortable creating.
Over the past few years, Square Enix has become increasingly concerned with the status of the game, now half a decade into development. A source says Eidos Montreal turned to a German investment firm for additional funds, something superiors within the studio claimed to be a common strategy in the industry and not cause for concern.
The current version of Thief barely resembles the initial concept, says a source. The vertical slice doesn't load inside Thief's current heavily modified version of Unreal Engine 3. Many programming tricks were necessary to run the current demonstration, like turning off non-playable character AI — the engine has trouble when too many characters are on screen.