Bridger's Oneironautic Expeditions

I'm walking around on some kind of game map, with wild terrain separated into areas of different enemy difficulty. Me and some others are searching for something, so we cross multiple rivers trying to find it. We end up in a high difficulty area and see a group of enemies wandering about a couple hundred yards away. I begin taking some rifle shots at them and land one hit before they're all coming at us. They fire back and I'm forced into cover. The other guys I'm with run around a corner on the hill we're on and I rush around to join them. I realize too late though that there is a large drop off right there and so I fall quite a distance into a large body of water.