Remedy Entertainment has a talk - actually two talks, one from 2013 and one from 2016 [0], about how they added D to their game engine, replacing a major subsystem, and then shipped a AAA title(Quantum Break) with it. The GC did not present a major issue although the talk notes that their solution was "unfinished" and got the result they wanted by wasting memory instead of what they initially aimed for(ARC, this is work-in-progress for D [1][2]). Most of the nuts-and-bolts work came from achieving smooth integration with the C++ codebase, and building for the release devices.

[0] http://dconf.org/2016/talks/watson.html

[1] https://wiki.dlang.org/Language_design_discussions#Automatic...

[2] http://www.digitalmars.com/d/archives/digitalmars/D/ARC_in_D...