Dude at the beginning. You can either kill him by squishing him with his own trap, or you can shoot him or beat him to death. Either way, he is not friendly because he's very scared.
He is the one that writes the message on the board in the tunnel near where you wake up. After getting a glider he powers up the Cyclops, who is now trapped in the ship.
Sam has been tortured because he does not believe in 'God'. Now, 'God' in the Ruins' Village is a powerful leader who lives in a pyramid and feasts on rage and victory.
Trekkie is a half human half goober who lives in the Village, hidden from the rest of society. If you repeat the dream enough times he will give you something special. If you dream too long he will fight you to the death.
Tea Master Edit
The tea master lives within your dream. He can count the number of times that you predicted the future (times that you died). Do not mess with him as he will most probably kill you.
Old man Edit
The old man waits in front of the temple, pondering on the existence of his God. Repeat the dream enough times and he will find out the truth.
Kids are lonely, sad, determined, and violent. They will do anything to get their revenge, even though they don't know who is responsible for their sorrow, and what to do to survive. Most probably they won't make it through.