Escape from Cnossus is a roguelike for the ZX Spectrum, made with Boriel’s ZXBasic compiler. It’s a minimalist coffeebreak game; I can finish it in about 40 minutes if I counted correctly. Source code is also available.
You can play the game online courtesy of the JSSpeccy emulator. However, I recommend downloading it. Code and assets available on GitHub.
release 2013-07-10a (tape file, source code and assets)
This is a survival game! Some monsters, generally the mundane creatures, drop useful items when killed, but most give you no benefit. It's best to avoid them unless fighting is the only way to reach the stairs. Even then, remember that monsters fear light: light a torch or what have you and they'll either become confused and attack less, or even run away entirely. Good luck!
Ossuary, a colorful graphical roguelike by Cyningstan.
See also Spectral Dungeons, the first game in the series.
If you like this game, there is now a desktop edition you can buy: