Planets is a simple game available for Windows, Mac, Linux and even Android.
The game is not completly finished, so some features are incomplete.
Java 8 or greater is needed to run the game on Linux, Mac and Windows
Processing is required in order to build the game
Just execute the application corresponding to your system, under the bin directory.
For Android, download the apk to your phone and install it (you will need to uncheck "Never install applications from untrusted sources" configuration option)
Click the "Jouer" button (Play in French)
Then you need to launch the satellite to the green planet, avoiding red planets attracting you.
You can press Space to reset the launch.
There is a Map Creation mode, but maps can only be played once at the moment and are not saved.