If a game like the original Doom is any indication, video games can be played on a wide variety of platforms and created with many different programs. With the Pokemon parody known as Fontemon, we now have a video game that's inside a font file, like the kind that lets you type in Times New Roman in a word processor.
Developed by Michael Mulet, Fontemon is a game you can play on the game's official page or anywhere you would use a font file, such as a word processor or image editor. Taking place in the fantastical realm of "Minnesota," you play as a ten-year-old who's given three of the titular half-font, half-monster creatures by Fred, the Fontemon Freshman, as you fight eight gym leaders for their badges. For most of the game, you advance the text by typing anything into the game, and at certain points you type a specific letter to make a decision. It's effectively a choose-your-own-adventure game, as there aren't any deeper mechanics to determine things like hit and critical chances.
But how does it work? There's a whole page explaining it on GitHub, but Mulet has a shorter explanation, as well. In the "font's" GitHub file, developer Michael Mulet explains that he created it "through the magic of ligatures, the thing that turns 'a and e' into æ." Except instead of replacing letters, he replaced the game's frames (of the animation variety) into each other to make the animations and branching storylines. Mulet says that in total, Fontemon has 4696 individual frames, 43 choices, and 1085 words of text.
You can play Fontemon on your computer by going to its official page here. If you'd like to download it, whether to play it offline or to experiment with the file for your own projects, the font file can be found on this GitHub page.