Here is the full list of all 13 Freedom Fighter achievements.
The first kill is the hardest.
You've broken out of your first prison cell!
Dead bodies are now your new hobby. Good job killing at least 50 enemies!
After killing over 100 enemies, your hobby of killing has became a natural habit.
After killing over 500 enemies, you can't imagine NOT killing! Great job!
You must be a Natural Born Killer! (At least 1,000 Enemies killed)
Saving prisoners could be your new thing. (Saved first prisoner)
People are starting to talk.. Callin' you some sort of savior or somethin'. (At least 50 Prisoners set free)
That's Captain Savior to ye! (At least 100 Prisoners set free)
You've been deemed the peoples hero! (At least 500 Prisoners set free)
The people have been saying you're heaven sent! Great job, Hero! (At least 1,000 Prisoners set free)
Holy Bahjeezus! You've managed to earn over 1,000,000 points, you're an animal!
You've broken out of at least 100 prison cells. You are a pick lock master!