I liked the bot destruction particles, as well as good sound effects.
The controls are not standard and for me personally the most inconvenient, I'm not sure maybe I had some kind of bug, but should I turn the camera with the mouse wheel and turn the weapon by moving the mouse? If you use the built-in 3D, then there are very convenient extensions such as a third-person camera and top-down movement, if you add them, you will get a pretty good shooter.
Good luck!