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.
You can play the game online courtesy of the JSSpeccy emulator. DOS edition via the Warajevo emulator. Code and assets available on GitHub.
It's relatively slow on older machines.
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!
From Indie Retro News, 2015.
As of autumn 2017, you can buy a desktop port with redone graphics and other improvements.
You'll need an emulator for the ZX Spectrum 48K to play the TZX file; FUSE works well, but there are many others out there. The DOS edition was built and tested under DOSBox, but it might just run natively on Windows XP and older. Use F10 to quit. And thanks for getting this far!