You are a machine disguised as a living beeing send from the future. Your goal is to prevent what is yet to happen by killing a future Nanotrasen hero. After spawning in you will have nothing (not even clothes) so it's a good idea to get something to wear as soon as possible.
The machine in you
Since you are a robot skeleton merely wearing a fleshsuit you have significantly more durability than normal crewmates. You are harder to stun and most physical damage types are significantly reduced. No lungs, no need to breathe. Chemical hazards are something you can only laugh at. Your only weakness is electricity so better get yourself some insulation.
When your cover blows
Should your body take too much heat or Brute damage, your true form will be revealed. You will only be able to Punch anyone in your way to death. Once you lost all the tissue around you there is no way of reattaching it, so try to delay this as long as necesarry.