The Bonus Stage (Bonus Phase, Bonus Round, etc.) is a recurring element of the Balloon Fight series, appearing in a majority of the games.
In the Bonus Stage, it most commonly is just a single, non-scrolling screen with four pipes in the stage. Twenty Balloons will come out one-by-one and you must pop all of them. In Balloon Fight (NES), the stage will appear in game modes A and B after every three stages completed, and you can get a "Super Bonus" if you collect all twenty balloons. In Balloon Kid, there will sometimes be Game Boy systems around some stages and you will be transported to a Bonus Stage if you walk into them. In these stages, letting one balloon pass the ceiling will end the stage and you will be sent back into the normal level. In Nintendo Land: Balloon Trip Breeze, there will be a Bonus Stage level at the end of Day 3: Morning, and another with eight pipes at the end of Day 7: Morning. In Vs. Balloon Fight, later levels of the Bonus Stage have more than four pipes.
In the original Balloon Fight (NES), the pipes are gray and the ground and balloon color changes depending on how many times you have gone into the Bonus Stage. In Balloon Kid, the screen can scroll vertically, and the stage is considerably thinner than usual, due to the smaller resolution of the Game Boy. In Balloon Fight GB, the color remake of Balloon Kid, the pipes on the ground are green. In Balloon Trip Breeze, the pipes are yellow and there is no ground or platforms, as well as a wider screen and no scrolling.
- The green pipes seen in Balloon Fight GB are likely a reference to the Super Mario Bros. series, and this may have been included because the group at Nintendo that created Balloon Kid, Nintendo R&D1, also created Mario Bros. and Super Mario Land 1 and 2.
- Although there has never been any obstacle in any Bonus Stage, in a later part of Balloon Trip Breeze there is a Bonus Stage scene where two unbreakable Balloon Breakers bounce around the screen. Also, the water is always open during the Bonus Stages in Balloon Trip Breeze.