I don't know if its just my machine, but the game ran horribly for me. Anytime I moved the mouse to look around the game would slow down to a few frames per second. And when I tried to move or sprint, the camera would bob like I was moving and the stamina bar would go down, but I wouldn't actually move anywhere. I think the movement detection must be incredibly delayed, because if I waited for about 15-30 seconds after moving, and didn't press anything else, I would suddenly find my character moving wildly in different directions. The jumping worked though, so maybe there's some other issue with the movement.
The only time the game seemed to run smoothly for me is if I stood still, and fired the pistol. Then it showed the bullets moving as it did in the videos on your YouTube channel.
Aside from the technical issues, I did like some aspects of the game. Overall it kinda reminded me of Elder Scrolls Arena and Daggerfall mixed with some of Bethesda's old Terminator games. The compass in the corner looks especially old school, that combined with the night scene and the trees and the head bobbing, it really gives off that old school vibe. Also the "study beats" music style fits surprisingly well with the atmosphere of the game.
The pistol kinda reminded me of the one from the original Deus Ex actually, don't know if that was a reference or influence for you but I thought it was neat.
Regarding the UI, I think the animated health and mana bars (I assume the red and blue balls represent health and mana) are really cool. The compass and flashlight icon are fittingly old looking, and the stamina bar, while maybe a bit plain looking, works for what it is.
I think the weapon selection bar (I think thats what the green bar at the bottom is) could use a bit more visibility, like maybe a border around it and maybe increase the alpha value. It's a bit hard to say with no items in it though so maybe I'm wrong.
The crosshairs for the pistol also seem to be a bit too high, it could be lowered somewhat. Maybe change move it down so that the top line of the crosshair is where the bottom line of the crosshair currently is.
I think this could be a cool game, but for me the technical issues drag it down quite a lot. Keep working on it though and it could be pretty fun.