Balloon Invasion is a great flash game where you are commander of an anti-aircraft defense fighting against waves of bomb-dropping enemy balloons. Created by top tier developer Game in a Bottle , this is a long game, with lots of options, including badges, upgrades, high scores, and hidden unlockable levels. It's a technically more advanced game than most indie web games, with higher end graphics and special effects, and some lower end computer users may have to turn down some of the options. Another similar turrent-type game is Stormwinds (play here)
You can play Balloon Invasion here at Meez.
Initial Hints and Tips (no known cheats)