Thanks for your support!
About the audio muffling - it might be caused by the game performance hit spike during enemy respawnings and NavMesh pathfindings tasks. You might wish to download & play offline version, performance will get better than browser play.
I may make the player able to shoot wherever he points to, that way the game will still be compatible with desktop/console/mobile envs, hopefully support 360 degree joystick to allow fine grained shoot aiming, and the game becomes more playable!