CastleOfDuck, from Korean developer newbieCAT, is a game in which the player is a duck defending a castle from invading turtles. It's similar to The Typing of the Dead, but instead of every enemy coming with a word or phrase attached, every enemy has a pattern attached, and the player must swipe that pattern on the lower part of the screen to attack.

As simple as the game is, with only a 3x3 grid of dots for making patterns with, the game is far from easy. Well, the first level is easy, but the difficulty quickly ramps up. Not only do enemies appear in greater numbers, there are different kinds of turtles. There are ninjas which have easy patterns but move quickly and other enemies which require multiple "hits", changing their displayed patterns each time they are attacked.

The game is free to download for both iOS and Android, and different ducky heroes can be purchased in-app for $0.99 each. The different ducks have different stats, passive skills, and active skills. Different environment skins can also be unlocked as a bundle for $0.99. Purchasing the environment skins will also remove ads, which pop up between every other level.