You can shoot a beam by dragging a stylus from lower side to upper side on silk screen area. Notice that the beam isn't shot if you drag over the silk screen area.

Enemies appear from top of screen. So, shoot the enemies. If an enemy reaches to bottom of screen, a shield is reduced. If the shield is nothing, the game is over.

Sometimes, a bonus character appears. (bonus) If this reaches to bottom of screen, you get a bonus (score or additional shield). I recommend that you don't shoot the bonus character.

You can pause the game by pushing hardware scroll button. Because silk button is invalid during playing the game, use silk button when pausing.