Oh man, I'm the first one giving feedback^^
First things first, I'm absolutely no shooter player and very bad at 3D jump n runs...so I suck at your game^^
Pretty solid approach to the topic, but imho using magic instead of a machine gun would be better fitting. Good thing is you start with a tutorial, so it was very easy to figure out what to do, right from the beginning.
Edit: Second to give feedback, had the page open for too long and realized after the post