Have lost instructions and can't res...

With the game off try the reset button then turn it on.

Or turn it on while holding the reset button.
Sometimes you may have to hold it in, sometimes just a quick press.

Also with the game on and not off remove the batteries. Leave them out for at least 4 minutes then replace them. If his doesn't work hold in the reset button.

It seems complicated because it sometimes is . I have one game that you have to turn it on while holding the reset button then holding down the A button, restarting it then pressing the reset button.

It sounds like in this case you may have to delete your game then start over. Resetting the game sometimes just momentarily resets the address bus (microchip) to zero then applies a lower voltage to basically be void of any hang ups due to power drain while not actually starting your game over.

Try several different methods of using the power button in conjunction with the reset button.