Nice that you added settings and different difficulty levels/input methods.
It is a nice shooter game and I think the mechanics are well integrated. Really liked playing it with the mouse actually! Also, I like the variety of patterns and enemies.
However, I could not fully understand what the second bar was for (just a second health bar?) and I did not always understand what was an enemy and what was not, maybe a small explanation on the various items would be nice to clear that up