How can i make it where the backround starts flashing white and black?

also: game going great!

lol use backcolor i think, make a loop of it switching back and forth, or if you want it to go for a certain amount of time do backcolor (stuff here) wait 10 (or whatever) backcolor (stuff) just keep doing that.

how can i stop it

just use M=MAINCNT REPEAT BACKCOLOR #WHITE WAIT 30 BACKCOLOR #BLACK WAIT 30 UNTIL MAINCNT - M > 300 adjust this to lengthen or shorten the flashing time