to activate secret costume on nano, click on HACK button then go to MAKE NANO SAY then make him say gigantGceMax22
Note 1: Some glitches may occur with the HACKNANO tab. Like there is a glitch that closing after before nano vanishes the cat. When the second dissapear sound plays and you already made the cat disappear and you closed the HACKNANO tab before nano vanished the cat then there may be a bring back button on the screen. Dont worry just open the HACKNANO tab and then close it and boom no bring back button on screen!
