The audio creates an unsettling atmosphere and the 'trailing' effect on the visuals is very nice. I like to 'teleport-to-kill' mechanic and the game is smooth and frantic. All together, pretty nice!
One small thing, I really don't get on with using Left-Shift alongside WASD (I can't be the only one?!). I'd prefer Left-Alt then I could use my thumb to alternate between that and space.