change texture; added level var
change hard text to string value; change text color
create level 19
refactoring wave contraller
create level 20
change level_1
change level 2-3
change level 4-7
change level 8-9
change control bar size
change level 10-11; change move control
change level 12; change rocker fly speed
change background paralax speed
change level 13; make defspeed of ship more; change extra damage from 15 to 10
change level 14
change level 15; fix small text size buffer bug
change level 16; make bullet speed a little more
change level 17
change level 18
change level 19