It’s all about nature and is both simplistic and beautiful.

Each puzzle is made from stunning wildlife illustrations from the 18th and 19th century by artists like John James Audubon and John Gould. Along with the picture, there is a detailed description about the animal.

There are two ways to put together each puzzle, the image or text for even a bigger challenge.

And for Earth Day, the puzzler has just gotten a great new update. There is a new puzzle pack—Echoes of Extinction. The pack features animals like the passenger pigeon, quagga, and dodo. All 10 of the animals were alive when their illustrations were made, but have since gone extinct.

The update also brings new app icons.

The Art of Fauna is for the iPhone and all iPad models. You can download the free app now and play the first 10 puzzles. Unlock more than 100 puzzles in the game for an in-app purchase of $7.99.

Optionally, you can also unlock each of the five biomes for a separate $2.99 in-app purchase.

A portion of every purchase will be given back to support elected wildlife conservation organizations.