LOL! The whole falling issue at the end is solved by walking with the triggers (RL+LR) pressed, and that's it, hahaha, it lets you maintain your balance, it's no big mystery.

A friend told me when I started, "I got bored because you just have to go from here to there," and I told him, let me give it a chance.

And I'm glad I did, the game is really enjoyable, and there are so many ways to play it. Now, in this last mission I have left, I have to attack a camp, and the dynamics change completely. I'm really looking forward to finishing it and playing the second one sometime. And well, the story is very good. Thanks for your comment!