On the Heart of Darkness: Carefully stay back and pick off each enemy. You don’t want them overwhelming you. There are save points in the safe houses. Use them to your advantage. If you choose to grab the briefcase full of diamonds, run back to the jungle on the way to the commanders and pick off the ambushers from there. Otherwise they’ll surround you. Other than that, just keep it focused and you’ll make it to the Jackal. Once you’ve met him, he’ll tell you to choose between a battery and the briefcase. Whether you choose to detonate the bomb or bribe the guards, you’ll unlock this achievement for completing the game.