Mac: At Lifehacker we're all about staying productive, but sometimes you just need to take a break. For a quick gaming pause, try this old-but-fun tip: with a few terminal commands, you can open up games includiing 5×5, Pong, Solitaire, Snake and Tetris and others in your Mac's terminal.
To start the games up, open Terminal (in /Applications/Utilities) and type
emacs into the prompt. Press Enter to open it up, press Esc then
x. Next, just type the name of the game you want to play and enjoy (note that different versions of OS X have different games, so see what you have first!). The games are simple and the graphics are not great but it is a perfect way to power down and relax without getting so engrossed in a game that you end up spending hours on it. Hit the link to read more, and have fun (but don't forget to work)!
How to Activate Hidden Mac Games in Terminal [Make Tech Easier]