The animate package makes text dance (e.g., M-x
animate-birthday-present).
M-x blackbox, M-x mpuz and M-x 5x5 are puzzles.
blackbox challenges you to determine the location of objects
inside a box by tomography. mpuz displays a multiplication
puzzle with letters standing for digits in a code that you must
guess—to guess a value, type a letter and then the digit you think it
stands for. The aim of 5x5 is to fill in all the squares.
M-x bubbles is a game in which the object is to remove as many bubbles as you can in the smallest number of moves.
M-x decipher helps you to cryptanalyze a buffer which is encrypted in a simple monoalphabetic substitution cipher.
M-x dissociated-press scrambles the text in the current Emacs buffer, word by word or character by character, writing its output to a buffer named *Dissociation*. A positive argument tells it to operate character by character, and specifies the number of overlap characters. A negative argument tells it to operate word by word, and specifies the number of overlap words. Dissociated Press produces results fairly like those of a Markov chain, but is however, an independent, ignoriginal invention; it techniquitously copies several consecutive characters from the sample text between random jumps, unlike a Markov chain which would jump randomly after each word or character. Keep dissociwords out of your documentation, if you want it to be well userenced and properbose.
M-x dunnet runs a text-based adventure game.
If you want a little more personal involvement, try M-x gomoku, which plays the game Go Moku with you.
If you are a little bit bored, you can try M-x hanoi. If you are considerably bored, give it a numeric argument. If you are very, very bored, try an argument of 9. Sit back and watch.
M-x life runs Conway’s Game of Life cellular automaton.
M-x morse-region converts the text in the region to Morse code; M-x unmorse-region converts it back. M-x nato-region converts the text in the region to NATO phonetic alphabet; M-x denato-region converts it back.
M-x pong, M-x snake and M-x tetris are implementations of the well-known Pong, Snake and Tetris games.
M-x solitaire plays a game of solitaire in which you jump pegs across other pegs.
The command M-x zone plays games with the display when Emacs is idle.
“Real Programmers” deploy M-x butterfly, which uses butterflies to flip a bit on the drive platter, see https://xkcd.com/378.
Finally, if you find yourself frustrated, try describing your problems to the famous psychotherapist Eliza. Just do M-x doctor. End each input by typing RET twice.