Rival balloon fighters. When you pop their balloons they parachute to solid ground and inflate a new balloon. Hit them a second time, or they will change colour and come back faster than before.
A giant, ugly fish that lives in the water. If the player or an enemy floats too close to the water it will try to snatch them up in its mouth.
In the 1 and 2 Player Games, spending too long on one screen will cause the clouds to shoot Lightning. It floats around, bouncing off the sides. If the player touches the Lightning, he will be instantly defeated. In Balloon Trip, hundreds of Lightning sparks stand between you and a high rank.
A spinning obstacle found in the later stages. If a player or enemy hits it, it starts spinning wildly, sending anyone who touches it flying off in unpredictable directions.