I really liked the gesture controls, they add so much depth to the simple act of shooting and reloading. I also think that making the game an on-rails shooter was a great choice, it really lets the unique mechanics shine. My only issue with the game as others have noted, is the difficulty. In particular, the dust, while great for atmosphere, makes enemies difficult to see, and almost invisible when directly in front, where the dust effect is stacked. This could have been remedied by drawing the enemies as silhouettes on a higher layer when the dust gets thick.
Overall, great gaem!