Keep of the Mad Wizard is a single-player text-based RPG of the dungeon crawl variety, with randomized elements. It comes in a gamebook-like format, and can be played online or offline.
The game is meant to be replayable. It's a coffeebreak game that can be completed in about 10 minutes once you are familiar with it. But each time you'll get a different challenge, so pay attention to your resources! (See the built-in help for how to play.)
System requirements: Any modern web browser. Firefox 45 and Opera 45 both work, not sure about older versions. It also runs on mobile devices, though a screen width of 1024px is ideal.
For developers: As stated in the credits, Keep of the Mad Wizard is made with Tweego and released under the Artistic License 2.0, a copy of which is included in the source archive. You can compile the latter with tweego -o mad-wizard.html src. No special options are needed, but you need the default SugarCube 2 format installed.
As of 10 April 2019, the game is considered complete, barring tweaks and bug fixes.