Right above that platform is an ESP enemy and a battery. Get ESP, and carry over the battery to where the final code cube is (in the teleporting door thing). Then stand right above the metal platform in the door and use ESP to hit the switch through the wall. Then just get the Code Cube, and keep walking right. There's a hidden Robobot Armor inside a crate.I see the gold sticker in 2-1 but its underneath a platform with two screws to undo at the top but theres no robot to use and the last door is the stage exit.