it may Appear like Sleep mode but the screens arent Dimming/turning off and the 3DS isnt actually going into sleep (i timed my 3DS from full to Blinking Red with a gba in "Sleep" (lid closed) vs a 3DS game in Sleep mode. and the 3DS w/ a GBA Game running Died faster.My GBA games seem to have a sleep mode with all of the CFW's that I've tested.