I dig the game but the bullet and projectiles sound fx are really weak. Same can be said for when enemies die ( the floaty one that shoots eyes is ok though ) They could use some additional sounds when attacking/pursuing  as well, like for the chainsaw guys you could give them chainsaw rumbling sounds and when they hit the player the sound of the saw rev's up followed by some squishy sounds like they've cut into you. 

Extra details for the pistol could be to have the mouth of the gun moving when not firing, then when you shoot have blood dripping out it's mouth as its firing which fade away after you've stopped.