We called it "sneak" in one of the descriptors to try and clue in that it's for stealth, it effectively just lowers the aggro range of the Jermazoids, the goal is to get to the end of the valley of sorts and there's a floating orb to get the end screen. If you've played the first 10 seconds though you get the idea of what the entire game is, only thing you really miss is the picture that shows up on screen when you get to the end, which honestly isn't even worth doing.