There is not much known about the characters. Player One is a male with Mike Three Beta on a plastic wristband. Player two is a female with Echo Five Zeta on a plastic wristband. The two have no recollection of anything before waking up in research facility. There is a clear difference between the characters though. Mike is stronger and therefore can lift/move heavy objects where Echo is small so she can fit through tight spaces.
There is also not much known about the research facility or the city in which the players are navigating. There is no explanation to why both the facility and the city are in ruin. The research facility is condemned and near the point of collapse. The city itself is covered in toxic chemicals, and endless abysses. The surroundings suggest that it is the result of a global war.