Jampot, ForlornCreature would be the better guy to ask. He's got tons of behind-the-scenes stuff where he talks about his sound process. You'll have to dig around to find the videos, but once you do it'll be worth it.
Now, as for this short, the most evident omission is jungle ambient noises. No birds, no bugs, no scary creatures, no plant movement, no wind, no squishy mud, nothing. If you want us to believe in the jungle setting, you have to appeal to both sight and hearing, or the illusion is destroyed. It looked like a great jungle, but if I closed my eyes, I'd have no idea where it was set. You also want various layers to the sound. For example: In the fog, you had a solid wind sound, with little variation. That would be fine, if there were also other wind noises that faded in and out, and side-to-side. With several layers, you get a fuller sound, and one with a lot more detail and complexity.
Another thing is that the whoosh sound just don't sound right. It sounds too thin, with no weight or power behind it. This pack has some great ones, although I've gotten to the place that I overuse them, so watch out for that. You should also remember that everything can potentially make a noise. Stuff falling to the ground, clothes rustling, people grunting while hitting/getting hit. The more sounds the better, just keep the volume balance correct. Basically, you want viewers to have a perfect view of what's going on even without the video.
I suggest having the music track, at least two ambient/atmospheric tracks, and two or three for main/foreground type sounds.
Fights will use a lot of foreground sounds, while slower scenes will need more in the background. Oh, and the awesomeness of stereo sound can never be understated. I highly suggest putting out the effort to place sounds left, right, and all over the place. I did in Secrets in the Shadows, and it sounds much, much better for it.