Monster Ape Easier Win
There are a lot of things that you need to do to win, it took me a lot of tries to win but I managed:
1st: make sure your ammo is completely full before entering hole.
2nd: when the ape bursts out of the door, use eco reflexes right away, run a few feet away and launch the red eco ball out towards it and then shoot it with the blaster or vulcan fury.
3rd: run around in medium sized circles and punch or spin kick it every time he tries to pound on you.
4th: some times use the eco sheild and the eco structures, make sure you buy anything from keira that says eco construct and it will help you.
5th: repeat previous steps.
there you go hope that helps.