Gunbrick dev Nitrome unleashes symbol squiggler Magic Touch: Wizard for Hire on iOS
The goal is to fend off enemies who are floating down from the top of the screen, by squiggling out the symbols that are shown on the sides of their balloons. If an enemy lands on your castle wall, it's game over.
You'll also unlock spells to slow down time, turn enemies into frogs, summon a dragon, cover the floor with fire, and turn the castle turrets into gun turrets. These are bought with coins - either earned in game or purchased through IAPs.
You can also buy new backgrounds, and remove the adverts. You can get Magic Touch here.