Added sound settings and fixed some enemies

There were a few enemies that has an incorrect direction configured to them, causing them to float off screen (and therefore missed points) That has been fixed. 

Added some sound settings to adjust the volume for music and sound effects. This setting is not saved and will need to be set again when the game is launched.

Edit: Quick fix introduced cause I'm a dummy and didn't realize the animation player was not correctly reseting default values.