AMAZING
Great concept, fantastic gameplay and lasted for ages. Everything that I like to see in an awesome game like this.
There was one thing that I noticed that you couldn't do though, you couldn't hit people with your shovel while couching. I remember you could do this moneuver in Metal Slug (I used to do it all the time) but not in this. If you ever make a sequal, please include this.
Other then that, no objections what so ever. Fantasic work.