This is a very popular toy, originally made by Marx toy company way back in 1964. It is still on the shelves today, and affordable to play.
The object of the game is to knock your opponents head off…Technically your opponents head pops up on a spring.
Choose either the red robot, called (Red Rocker,) or the blue robot, (called Blue Bomber).
There have have been many versions of the toy over the years, but the parent company has stuck with the same concept since the beginning.
Here is a quick tutorial in this old T.V. commercial: