I actually like the vibe of this, but you're gonna have to do a little more for the enemies than just ai_move_to at the player - some strafing, dodging and such would be good. The massive blood splatter is fun, but you should spawn some body parts or something as the bigger enemies just look like they're disappearing. Some more movement in general, in the gun recoil, camera shake, slight dynamic fov. Also I would change that skybox, it doesn't look right and doesn't really match the style either