You are by far most vulnerable while teleporting. Also make sure that your laser is loaded so that you can minimize the risks.
- Not so bad. Easy to shoot. Does fairly little damage.
- You cannot shoot these. They can be pretty dangerous if you're standing still - teleporting or cracking codes.
- Sensor units. Does no direct damage to you, but reports your whereabouts and thus gathering other robots. I haven't found it very risky to be seen by these if you move swiftly.
- These are the worst robots 'cause they fire at you. They are sometimes difficult to shoot, as they do not fly at a constant height. They can be lethal if you are teleporting.