Alright, this game gives me motion sickness, but anyways on to the more important stuff.
The graphics are obviously from Minecraft. I can understand that was the point, but if i wanted to play Minecraft with a machinegun, I would have downloaded a mod for Mincraft.
The start menu has 2 fonts, both are annoying to read. I can understand the title looking cool from the normal font, but the normal font is just out of place, it looks like something that belongs on a toothpaste tube. At least change it to blood red so that it'll look more intimidating.
The start menu instructions, personally I prefer Instructions in a seprate menu. Having them scroll on the bottom works, but not when they're bouncing around like jelly beans! It would be better if they were just going in a straight line.
The player character looks extremely out of place. I don't even know what it is supposed to be. It looks like some frankenstein monster with jeans for legs. It doesn't even have animation, players just teleport a short space in some direction.
The UI looks out of place as well. I can't comprehend weird compass thing at the top left. The first three times I didn't even notice that there was text.
The gun you are holding is also out of place, it just doesn't seem right in the Minecraft world.
Moving is annoying, it's fine if you have a cursor to aim around the whole screen, but the screen has to not more while you're doing it. It's also fine if you use the mouse to move the screen around, but in that case you have to shoot only in one spot (ex. cursor in the middle you always shoot from the middle)
I don't understand why when you get shot it looks like bullet holes in glass, I mean the character looks like a creature of flesh and blood, and you're not in a robot or vehical, so whats with the glass?
The sound effects are annoying. Especially the scream when you die, what is that? It sounds like some sort of alien monster mating call. It wouldn't bother me so much if there was some sort of music to drown it out a bit, but there is non.
As a those, the game looks unfinished.
Half a star for effort, but please try harder next time.