Naturals is a puzzle game based on natural numbers. Start with a number, use the operators, hit the buttons, open doors and pass through the conditions to get to the exit in each level!
This brain teaser currently comes completely free (Free as in beer!) with fifteen puzzles and requires no special permissions to install. That means that you can comfortably install it on your device without worrying that something might happen.
The game will be regularly updated with new features and levels. To help me continue improving this game and making more free games available, please consider making a donation to the project. Think of it as buying me beer for the fun you had playing the game! The donation money will help me buy developer licenses for other platforms such as iOS and Windows Phone to make this game available on those as well. Thanks!
Also, by donating 20 euros or more to the project, you can get the full cross-platform source code of the game in C++, so you can use it in any commercial or non-commercial projects with no strings attached.