Like the activator, it was cool in thought, not in reality. What you had was a game of battleship, with sensors in it, that was supposed to replace the standard controller. You could punch at it, or steer with it, but neither really worked. What ended up happening was you getting your ass handed to you by every opponent in every game, whether it be boxing or racing. But the guy in the commercial just made it look so cool!
#4-NES-LJN Roll & Rocker
The Roll & Rocker is essentially a primitive Wii Balance Board. It ended up just being a d-pad for your feet. Imagine playing any NES game by shifting your weight, and you'll know why it didn't sell. Plus it could only support 100 lbs.
#3-NES-Konami Laser Scope
I don't know why Nintendo believes that normal controllers are so bad, but this accessory is a failure. I don't know who thought that yelling "Fire!" into a microphone to shoot is more fun, or more advanced that pushing a button. The little cross-hairs over his right eye are supposed to show where your aiming, but as with most NES accessories, it wasn't very accurate. All the Laser Scope made you do was lose your voice, annoy your parents, and hate the word "fire".