From Wikipedia:

The primary gameplay mechanic of Big Bang Mini involves the player using the stylus to shoot fireworks from the bottom screen to enemies in the top screen. While you are shooting fireworks, debris and sparks rain down from the top screen onto your character on the bottom screen, and you must again use the stylus to dodge the falling hazards. Big Bang Mini has four gameplay modes, multiplayer functionality, and over 90 levels of gameplay. Upon completing a level you will be rewarded by designing a Final Bouquet.