Hovering is a technique that is present in almost every Balloon Fight game.
Generally accomplished by tapping the A or B button repeatedly at a certain rate, Hovering simply allows the player to move horizontally without losing or gaining altitude. Although this was possible in all previous games, Balloon Fight for the Game & Watch was the first to actually describe it in the manual. In the manual, it says:
"Hovering: By repeatedly pressing the Eject button just as the jet exhaust smoke disappears, you can keep the Balloon Man hovering."
In the manual, it calls Hovering an "Advanced Technique", and also lists Diving below. Between most games, the rate required to stay hovering in place varies slightly. In Balloon Trip Breeze, lightly sliding up allows you to hover.