It's a creative use of the theme! Though I couldn't tell what the weapon type changed in the gameplay. The bullets weren't going towards the crosshair for me, and it was lagging a bit when spawning the enemies when there were a lot of them. I'd recommend using object pooling to spawn the enemies. Also I felt like the visuals were a tad too blurry for me. Still I had a lot of fun playing, and your 3d model designs are great!