Thanks to my good friend Davis, I recently discovered an outstanding computer game for Windows, Mac OS X, and Linux called Kerbal Space Program. KSP is a game where the players create and manage their own space program. Build spacecraft, fly them, and try to help the Kerbals to fulfill their ultimate mission of conquering space. The game is currently under heavy development. This means the game will be improved on a regular basis, so be sure to check for new updates. Right now, KSP is in Sandbox Complete state, but is available for you to try out and have fun with. The first versions are free to download and play, and will remain so forever. It’s also pretty hilarious.
Go try it out here: https://kerbalspaceprogram.com/index.php