First about the time, the fact that Ruvik/Ruben and Kidman have memories about "villagers" makes me wonder if it's set during the WWII era or something. Also, the weapons are not very modern, fitting the game's theme—— there are electricity in the game, though no visible advanced technologies like televisions or computers, so I'm amazed as how much a genius Ruvik must be to make a system such as STEM. I suppose at most 1960ish?
Of course, this is based on inside the STEM, at the time when Sebastian entered Beacon Mental Hospital, it should be at least 1990ish based on the technologies and such. I assume even later than that.
Ruvik, from my research, was 37 when he was used as the STEM's host, assume there's a margin of time between that and Sebastian being called to the hospital, 1960s must be close to it.
Now the setting... where is Krimson City in America? It's definitely not set in Europe, and judging by the aforementioned time setting, it would be by a river like most towns then(or am wrong to assume this?), maybe the Missisippi? Or it could be by the coast, somehow the game gives me an impression of a sea-side town... but it could be just me?
Anyone have an opinion on this? I would be more than happy to hear it. Thanks.