Air balloons are for whimps...party balloons are for risk-takers!
Flying around over a field while trying to pop your opponent's balloons is a lot more fun than it sounds, especially considering that they can fall into the water where a giant fish awaits its dinner! (mmm, dinner!)
In multiplayer, you're basically trying to do the same thing, except reap the benefits while the other guy--or girl--falls behind. I really like shoving the other player towards the water when we're both on the ground, just to watch them get eaten by the fish.
This is a really good game for the NES, so play it. If you have Animal Crossing for Gamecube, you can get Balloon Fight to play in your house. Now, go pop some balloons!