v1.3 has added background grid that changes slowly, in order to break from the all static style used in previous version.

the changing background alternates between on/off mode.

i also added a feature 'Q' button will pop up a dialog to allow user to confirm if they want to quit game.

the game also tries to clean up the images it creates, therefore should be more memory efficient... but this might be minimized due to unforeseen issues like screen sizes etc.