schoolos.github.io (Note: Verify active fork; original goes down often) This site mimics the look of a Windows 95 desktop inside your browser. The "All Games" folder on the desktop unlocks everything from Doom (the original) to Mario Kart fangames.
Many viral web games got their start or maintain official mirrors on GitHub. You can find them using the username.github.io/project URL format: github io all games link
Here is the informative story behind the "GitHub.io" gaming phenomenon. schoolos
The Ultimate Guide to GitHub.io Games: Where to Play and How to Find Them schoolos.github.io (Note: Verify active fork