It's a nice idea, but it needs some finishing up. There's a bug where it gets out of sync and thinks you are constantly pressing in one direction. You have to press the other way to fix it. Also, you need to have the ability to switch guns if you fail a level. Picking the wrong combo can kill you over and over until you get lucky. An end would be nice, too. 4/5 for a nice idea.
Difficult, but with a good learning curve and simple to pick up, very nice animation and graphic design, and good voice acting. This game isn't my cup of tea exactly, but it deserves a higher rating!