Biomechanoids (BMs) are machine/creature hybrids. There's small ones that function as mundane tools like toasters and TVs, small ones with more esoteric applications like emotional regulations, and large industrial ones. It's also technically possible to implant them into people as extra organs, but this is hard to achieve without triggering a massive immune reaction.
The game is set in California in 1993, in a city called San Eligio that exists just north of where San Francisco is in our timeline. (Replacing the Grizzly Island Wildlife Area, to be precise.)
The setting diverges during the colonization of the Americas, as Spanish conquest of the Aztecs failed partially, and the subsequent conquest of the Maya failed entirely. As a result, Mexico is a much bigger and stronger country, incorporating what would be the southernmost states of the US, but not incorporating southern Mexico. Mexican culture is not very christianized and much more Aztec in flavour, and this also influences southern US culture. The r