GalaxyShooter.bas Update

*Loaded default background image
*Made main menu
*Made a "Play Game" button for the main menu
*Made a menu bar for the game
*User can set/change the game background
made background image

Drew default background image "space.bmp".
Drew default asteroid
drew ship sprites

drew:
*ship_down
*ship_down_on
*ship_up
*ship_up_on
*ship_left
*ship_left_on
*ship_right
*ship_right_on